Milgard vs. Cascade vs. Amsco for California Apartment Compl

[hawaiian23]

Hello! I need some advice on which window brand to replace 38 windows and 4 sliding doors with. I've received the following quotes:

Brand Model Price Glass Size STC Rating
Milgard Styline $25,635 1/8" over 1/8" 30
Cascade Win-Pro $18,110 3/8" over 1/8" 29
Amsco Studio $14,677 1/8" over 1/8" 25
Amsco Studio $16,899 1/4" over 1/4" 33

I am wondering why the prices have such a huge range. Is the Amsco quality that much less than Milgard? Also if Amsco can get me a sound rating that high for that price, then I am tempted to go with them because I have a few units that are right on a busy street and difficult to rent because of it. Please let me know what you all think of these brands! I am looking for a good balance between quality, price, and STC rating. Obviously lacking in knowing the true quality of these brands. Thanks for your help!