well, this has turned into one of the most uninformed posts ever. Kai and supermac are 2 of the few not talking out their asses. My basic turbo setup (that has gone basically unchanged for about a year) cost me about 5-600 to throw together using a used T3. I ended up building the hell out of the engine, and now I'm running hondata, so that shot the costs up about 2500, but well worth it to know I can boost 15lbs and not worry about it.
If you're just doing a bolt on kit, it's uber cheap to do it yourself. Igo4bmx also nailed it on the head. Piece all this shit together and save a ton. Also, using stock parts from other cars is a great way to save money. I was running an audi 5000 intercooler, and loved it. When I went to the johnnyracecar IC, I had a big pressure drop. Safer, cooler, but not as quick. And my dsm BOV has been kicking ass. Why spend $200 on a bov when you can get a dsm one for about 40 bucks? If you're boosting less than 12lbs, you don't need anymore. Why be a moron?