"The whole is more than the sum of its parts"-Aristotle
Being a figure collector is full of risks. Especially those of us that live outside Japan. Unless there're stores in our region where we can go see the figure itself, or we have someone we know in such regions, our only source is online sites.
(Note: Store you can physically go buy figure doesn't equal 100% true -- retailers can get fooled bringing in bootleg too!)(like the other store in our building with hobby stuff, either knowingly or unknowingly sells bootleg). Even that legendary Eren figure XXXD (recently saw those obvious fake Sword Art Online figures (what's it supposed resemble? Figuarts?)).
So!
Just wanted to share some recommendations on buying figures online that I've found out over the years.

Uzuhi's advices to buying figures online:
Be wary if ---
1. Price is too low to be true
Tis obvious golden rule of all online shopping.
(sidenote: Be aware of shipping price too. Figure price could be low, but shipping could be the catcher)
2. Seller either is new or has low rating
・In case of places like ebay and amazon, always check seller's rating. Unless you personally know the seller, better to avoid just launched sellers, and obviously those with very low rating. Also better that the seller's rating be based on high number of votes (like if only 10 people have rated the seller, even if they have a high mark, be careful)
・As in cases of sites that sell directly, try searching online if there have been any reports of pirate-version sells. And, be sure they accept returns, just in case.
(*↑This is also true of pre-orders. Pre-orders completely rely on trustworthiness of retailer/sellers)
3. Combination of Product photos are using official homepage photos + unrealistically low price
・Especially if the price is way low, safer that the photos are of the actual product being sold. Official site photos + low price, better avoid.
・Listings using official photos can still be legit. In fact most listings use official promo photos instead of their own. What I'm warning about are ones with the inexplicably unreal low prices. If the price seems reasonably real enough, even if the listing only shows official photos, can very well be okay. What price seems "reasonable real" will depend. Probably something less than 85% of actual price may be questionable? (less than 50% out of the question)
Photos of figure being sold & photo of package (box) is best!
4. Combination of Country of origin is China + unrealistically low price
Reaalllly sorry to sound prejudiced...but... origin China, Taiwan, Singapore, are risky (in combination with low price, that is)
・Most sellers very honestly note in the product description whether it's a authentic or not (like saying "Chinese reproduction", "China version"). No description, be scrutinous. Try contacting seller if unsure.
However, I did have a time where the seller listed the item as genuine but was actually bootleg. Figure was obviously warped and disfigured (no pun intended). (The fact that the inside wrapping was saran-wrap should've been a giveaway huh (=□=;)). Fortunately was returnable but had to pay shipping fee :/
(maybe they just didn't know, but it went back up right after as "genuine" again -- later found that lots of this seller's reviews reported products fake (and I mean like over 30 reviews))
(↑this was bought on Amazon btw)
5. Popular items listed at extremely low price
Popular products = more knock-offs. Loooots of fake Nendoroids out there. One Piece and Attack on Titan goods are notorious for having bootlegs.
・Example 1: Right after Attack on Titan key chain mascots by Takara Tomy were shown at a convention, they starting appearing listed as "on sale" (not pre-orders)(and I mean this was within DAYS). Official street date was 3 months later XD
・Example 2: Ebay search "Snow Miku Nendoroid" --- see the huge range? XD
・Example 3: Levi & Eren Nendoroids -- members of the BOOTLEG HALL OF FAME XXD
・Example 4: Attack on Titan: Colossal Titan Nendoroid --- wrong box (real is gray horizontal box) & missing pieces (real has a third titan) & wrong display (real original packaging uses the realistic face, not the cutey big-eyed one on the front)
High flags that item is bootleg----
6. Product DOESN'T EXIST!!
Most are obvious. If you haven't heard of it, or you're seeing it for the first time, google and check if it even exists.
・Example 1: Zoro Nendoroid --- One Piece Nendoroids don't exist XXD
・Example 2: Code Geass: CC Nendoroid -- doesn't exist. Official release is Chibi-Arts. Knock-off + they got the manufacturer wrong XD WOOOPS!
7. Package seems wrong -such as missing designs or stickers
If package photo is given, judge what you think. Most have a copyright sticker somewhere. Watch for things like title logo looking weird (like as if it was printed on by a low-quality printer), wrong title all together, wrong product name (like mislabeling Nanorich or Cu-Poche as Nendoroid), manufacturer not written, etc... Use your instinct!
・Example 1: One Piece figures must always have a Toei Animation license sticker
・Example 2: DABER ---need I say more?
8. Package is not in original box
Sellers can mistakenly list manufacturers, but boxes can't lie XD.
・Example 1: Sakura Miku Nendoroid, 櫻ミク ねんどろいど? hmmm, perhaps it's just they put a real one in a Chinese box to help local buyers, maybe not? (・3・) Just kidding, 100% bootleg.
・Example 2: Bunch of One Piece figures stuffed into a bag. This isn't being sold as "genuine", but just showing what can happen XD

All in all, photos of the actual figure & photo of the box is best.
See the photos and be your own judge. Try searching & comparing to other images.
----
Just something something to note---
There are cases where the official homepage photos or proto-samples don't resemble the actual figure. Actually more often than not. Even 100% legit ones. Search online if you think there's something wrong, and read other reviews.
Example 1: Serial Experiments Lain: Lain (manufactured by Vice) -- sample photos, actual figure
Example 2: At my job, there was a figure that I thought looked awkward. I called the supplier, they guaranteed authenticity. I also searched for reviews online, saw others with same opinions, and confirmed it was indeed a real version.
This was about Gintama: Kyubei (by Alphaxomega). It looked different than photos of what was shown at conventions but was authentic.
(Tentative) Example 3: ...Sailor Moon: Tsukino Usagi "Sekai Seifuku Series" (by Megahouse)-- looks a little bit different?..? (・・)????
・And! Each one (all legit) can be slightly different. This is just luck of draw.
Example 1: Shining Wind: Clalaclan Swimsuit ver. (by Alter) -- Review 1 (fine), Review 2 (differences in upper&lower torso colors) (site pours contensedmilk on figures, caution if you find this offending or gross!)
Example 2: Gintama: Hijikata Toushirou ver.2 (by Megahouse) -- ① ②, slight differences in jacket line's touch ups
・Some manufacturers are better at avoiding such deviations from from sample photos, and significant individual quality variations. Super major ones like Alter, Megahouse, Kotobukiya, Good Smile Company are usually good at quality checking products as they come off the product line. Some others, like some less major line companies (Griffon, AmiAmi, Alphamax), ones that usually focus on smaller items (Yujin (Takara Tomy), Bandai), prize (=crane game figures (Banpresto, SEGA)), can be mmmmmm, not so thorough checking. ***But again, major DOES NOT guarantee superb, minor does not mean slack, just stating that overall reputation wise, this is the sum of opinions I've heard.
Just wanted to note ↑, though you guys probably already know all this :D

Ultimately, you be your own judge! It's yours after all!
----------------
This is all just if you are looking for genuine official licensed versions that were manufactured by licensed makers.
If you're okay with cheaper knock-off editions, no need to worry! There is nothing wrong with that! To each his own! There are times where you want a figure but can't afford authentic ones! And even if you know it's a bootleg, if you like it, it's yours to choose. I personally would like to urge you to get authentic ones just so you can show support for the creators, but if that's not possible, it's yours to choose.
All these notes are just out of personal experience. Meaning, obviously no written-in-stone-true-of-universe stuff. Just wanted to give some advice to those fellowspecial category of nerd-ery figure collectors. Again, out of personal experience.
AND! Though I highly doubt this'll happen - I can't bear responsibility if it turns out these advises don't work. Use your own instinct!
Links:
・Bootleg warning list by manufacturer: Good Smile Company Bootleg Warning list
・Bootleg warning list by manufacturer: Alter (*Japanese)
・Bootleg warning list by manufacturer: Gunpla (Bandai)
・Most images (those without links) were from here.
・Sites listing bootlegs: Himajin Shokuhou, News Channel
・Sites listing bootlegs (English): Figure.fm, Nuts for Anime Figures
(Last edited-updated: 4/4/15)
(Note: Store you can physically go buy figure doesn't equal 100% true -- retailers can get fooled bringing in bootleg too!)
So!
Just wanted to share some recommendations on buying figures online that I've found out over the years.

Uzuhi's advices to buying figures online:
Be wary if ---
1. Price is too low to be true
Tis obvious golden rule of all online shopping.
(sidenote: Be aware of shipping price too. Figure price could be low, but shipping could be the catcher)
2. Seller either is new or has low rating
・In case of places like ebay and amazon, always check seller's rating. Unless you personally know the seller, better to avoid just launched sellers, and obviously those with very low rating. Also better that the seller's rating be based on high number of votes (like if only 10 people have rated the seller, even if they have a high mark, be careful)
・As in cases of sites that sell directly, try searching online if there have been any reports of pirate-version sells. And, be sure they accept returns, just in case.
(*↑This is also true of pre-orders. Pre-orders completely rely on trustworthiness of retailer/sellers)
3. Combination of Product photos are using official homepage photos + unrealistically low price
・Especially if the price is way low, safer that the photos are of the actual product being sold. Official site photos + low price, better avoid.
・Listings using official photos can still be legit. In fact most listings use official promo photos instead of their own. What I'm warning about are ones with the inexplicably unreal low prices. If the price seems reasonably real enough, even if the listing only shows official photos, can very well be okay. What price seems "reasonable real" will depend. Probably something less than 85% of actual price may be questionable? (less than 50% out of the question)
Photos of figure being sold & photo of package (box) is best!
4. Combination of Country of origin is China + unrealistically low price
Reaalllly sorry to sound prejudiced...but... origin China, Taiwan, Singapore, are risky (in combination with low price, that is)
・Most sellers very honestly note in the product description whether it's a authentic or not (like saying "Chinese reproduction", "China version"). No description, be scrutinous. Try contacting seller if unsure.
However, I did have a time where the seller listed the item as genuine but was actually bootleg. Figure was obviously warped and disfigured (no pun intended). (The fact that the inside wrapping was saran-wrap should've been a giveaway huh (=□=;)). Fortunately was returnable but had to pay shipping fee :/
(maybe they just didn't know, but it went back up right after as "genuine" again -- later found that lots of this seller's reviews reported products fake (and I mean like over 30 reviews))
(↑this was bought on Amazon btw)
5. Popular items listed at extremely low price
Popular products = more knock-offs. Loooots of fake Nendoroids out there. One Piece and Attack on Titan goods are notorious for having bootlegs.
・Example 1: Right after Attack on Titan key chain mascots by Takara Tomy were shown at a convention, they starting appearing listed as "on sale" (not pre-orders)(and I mean this was within DAYS). Official street date was 3 months later XD
・Example 2: Ebay search "Snow Miku Nendoroid" --- see the huge range? XD
・Example 3: Levi & Eren Nendoroids -- members of the BOOTLEG HALL OF FAME XXD
・Example 4: Attack on Titan: Colossal Titan Nendoroid --- wrong box (real is gray horizontal box) & missing pieces (real has a third titan) & wrong display (real original packaging uses the realistic face, not the cutey big-eyed one on the front)
High flags that item is bootleg----
6. Product DOESN'T EXIST!!
Most are obvious. If you haven't heard of it, or you're seeing it for the first time, google and check if it even exists.
・Example 1: Zoro Nendoroid --- One Piece Nendoroids don't exist XXD
・Example 2: Code Geass: CC Nendoroid -- doesn't exist. Official release is Chibi-Arts. Knock-off + they got the manufacturer wrong XD WOOOPS!
7. Package seems wrong -such as missing designs or stickers
If package photo is given, judge what you think. Most have a copyright sticker somewhere. Watch for things like title logo looking weird (like as if it was printed on by a low-quality printer), wrong title all together, wrong product name (like mislabeling Nanorich or Cu-Poche as Nendoroid), manufacturer not written, etc... Use your instinct!
・Example 1: One Piece figures must always have a Toei Animation license sticker
・Example 2: DABER ---need I say more?
8. Package is not in original box
Sellers can mistakenly list manufacturers, but boxes can't lie XD.
・Example 1: Sakura Miku Nendoroid, 櫻ミク ねんどろいど? hmmm, perhaps it's just they put a real one in a Chinese box to help local buyers, maybe not? (・3・) Just kidding, 100% bootleg.
・Example 2: Bunch of One Piece figures stuffed into a bag. This isn't being sold as "genuine", but just showing what can happen XD

All in all, photos of the actual figure & photo of the box is best.
See the photos and be your own judge. Try searching & comparing to other images.
----
Just something something to note---
There are cases where the official homepage photos or proto-samples don't resemble the actual figure. Actually more often than not. Even 100% legit ones. Search online if you think there's something wrong, and read other reviews.
Example 1: Serial Experiments Lain: Lain (manufactured by Vice) -- sample photos, actual figure
Example 2: At my job, there was a figure that I thought looked awkward. I called the supplier, they guaranteed authenticity. I also searched for reviews online, saw others with same opinions, and confirmed it was indeed a real version.
This was about Gintama: Kyubei (by Alphaxomega). It looked different than photos of what was shown at conventions but was authentic.
(Tentative) Example 3: ...Sailor Moon: Tsukino Usagi "Sekai Seifuku Series" (by Megahouse)-- looks a little bit different?..? (・・)????
・And! Each one (all legit) can be slightly different. This is just luck of draw.
Example 1: Shining Wind: Clalaclan Swimsuit ver. (by Alter) -- Review 1 (fine), Review 2 (differences in upper&lower torso colors) (site pours contensedmilk on figures, caution if you find this offending or gross!)
Example 2: Gintama: Hijikata Toushirou ver.2 (by Megahouse) -- ① ②, slight differences in jacket line's touch ups
・Some manufacturers are better at avoiding such deviations from from sample photos, and significant individual quality variations. Super major ones like Alter, Megahouse, Kotobukiya, Good Smile Company are usually good at quality checking products as they come off the product line. Some others, like some less major line companies (Griffon, AmiAmi, Alphamax), ones that usually focus on smaller items (Yujin (Takara Tomy), Bandai), prize (=crane game figures (Banpresto, SEGA)), can be mmmmmm, not so thorough checking. ***But again, major DOES NOT guarantee superb, minor does not mean slack, just stating that overall reputation wise, this is the sum of opinions I've heard.
Just wanted to note ↑, though you guys probably already know all this :D

Ultimately, you be your own judge! It's yours after all!
----------------
This is all just if you are looking for genuine official licensed versions that were manufactured by licensed makers.
If you're okay with cheaper knock-off editions, no need to worry! There is nothing wrong with that! To each his own! There are times where you want a figure but can't afford authentic ones! And even if you know it's a bootleg, if you like it, it's yours to choose. I personally would like to urge you to get authentic ones just so you can show support for the creators, but if that's not possible, it's yours to choose.
All these notes are just out of personal experience. Meaning, obviously no written-in-stone-true-of-universe stuff. Just wanted to give some advice to those fellow
AND! Though I highly doubt this'll happen - I can't bear responsibility if it turns out these advises don't work. Use your own instinct!
Links:
・Bootleg warning list by manufacturer: Good Smile Company Bootleg Warning list
・Bootleg warning list by manufacturer: Alter (*Japanese)
・Bootleg warning list by manufacturer: Gunpla (Bandai)
・Most images (those without links) were from here.
・Sites listing bootlegs: Himajin Shokuhou, News Channel
・Sites listing bootlegs (English): Figure.fm, Nuts for Anime Figures
(Last edited-updated: 4/4/15)