indecision

Ok, so I've been on the interwebs for the past couple hours looking at/for a cheap, affordable formal dress.
And have found the following:

Dress 1 (in this blue or a kiwi green):
Price: $49.99 (sale from $149.99)
My issues with this dress:
-It's LONG. I will need to hem it.
-One of the more pricey options

Dress 2 (in red or lilac):
Price: $49.99 (sale from $149.99)
My issues with this dress:
-I don't know what it looks like in red or lilac.
-One of the more pricey options

Dress 3 (in navy or lilac):
Price: $39.99 (sale from $119.99)
My issues with this dress:
-It's LONG. I will need to hem it.
-I don't know what it looks like in navy or lilac.

Dress 4 (will take any color suggestions except pink):
Price: $48
My issues with this dress:
-I don't know what it looks like in any of the colors.
-One of the more pricey options

Dress 5 (black or burgundy):
Price: $34.99 (sale from $59.99)
My issues with this dress:
-I don't necessarily like that it ties in the back I think the knot would bug me
-I'm worried that my back will look pudgy.

Poll #1250406 Dresses

Which dress would I look best in?

Dress 1
1(20.0%)
Dress 2
0(0.0%)
Dress 3
1(20.0%)
Dress 4
2(40.0%)
Dress 5
1(20.0%)
None of the above
0(0.0%)
More than one (please comment with which ones)
0(0.0%)

Which dress should I buy?

Dress 1
0(0.0%)
Dress 2
0(0.0%)
Dress 3
0(0.0%)
Dress 4
2(50.0%)
Dress 5
1(25.0%)
None
1(25.0%)