sed is clumsy, but here is what I could get -
sed 's/.*\(Apple\)[^:]*:"\([0-9]*\)".*/Enter product ID: \1\nYour product ID is: \2/' 3
Enter product ID: Apple
Your product ID is: 2134
sed 's/.*\(Mango\)[^:]*:"\([0-9]*\)".*/Enter product ID: \1\nYour product ID is: \2/' 3
Enter product ID: Mango
Your product ID is: 4567
explanation : substitute the string Mango : with -> Your product ID is: Mango Your product ID is : \1 and \2 save the matched expression in (..) for later use.