how much does one of these systems go for? any sites with more info on these? thanks alot

 

http://www.yoshimura-rd.com/default2.asp

It depends on which bike and what you buy. They offer slipons and full systems. Slipons can range from 300-500 for aluminum, carbon fiber, titanium etc.
Complete systems can go for two to three times that, depending on which bike it is for and the finish you desire.

They have an online store, but i dont know if they are the cheapest or not.

There are several online discount parts suppliers. I heard starcycle.com has pretty cheap prices on exhausts. I would say find the one you want and shop around to various online vendors.

Good luck.