does anyone know what the quality of the us-audio subs is like? i know of someone selling a 15" for $50 and am wondering if its worth getting? im pretty sure they are from autobarn but i dont know if they are one of those cheapo brands or not?

Depends on the series.. Some are OK others are not so good...
and why go a 15inch.. 12inch is more then sufficient...

why get a ferrari when a lada will do the job?

why get a ferrari when a lada will do the job?
Cause Lada's are more reliable then Ferrari

I would try to stay away from us-audio. but $50 isn't much so you can't really go wrong.

i personaly dont think they sound that good at all, better of saving up to around the 90.00 and buying a brand new clarion 12"

If your desperate go for it but i personally think their subs sounds horrible.