Hooker mufflers. Cheap and sound like flowmasters. There is alot of "cheap alt. out there. Cut and paste in some mufflers would be the cheapest.

I had a hooker catback on my 2000 Trans Am, they sounded very nice!! Up too you though if you like the chambered sound or straight throw sound.

Here is some ideas.

http://www.jegs.com/webapp/wcs/store...10265_-1_10245