you can get a pretty decent exhaust setup for 800 bucks. it all depends on what you want to do. if your just interested in changing the cats, just go ahead and replace them with some OEM style, or some high flows. Im not sure how well the high flows do for emissions, and from what ive heard, CT can be a real bitch about it. some shorty headers, new y pipe, high flows, and a nice muffler sounds like a good idea, and might put you right around 800.. im sure someone else will jump in that has mroe experience with exhaust