As mentioned, given your limited wrench-turning skills, don't buy one that isn't absolutely complete, turn-key, and without issue. That'll eliminate 95% of the turbo foxes you'll find. It's going to take you a long time to find this car, btw. Know every component in the build, including H/C/I, turbo kit, turbo, exhaust system, computer/tuner, fuel system, & ignition system. If you see any shortcuts or low budget stuff, skip it! I've never seen a decent low-budget turbo fox. It's either done right, or it's crap. This is going to require either extensive research on the individual car or extensive knowledge of the fox aftermarket. We can help you on that part if you post the info on the cars you look at. Make sure that the block, fuel system, and chassis support the power of the build. Hellion, Cartech, HP Performance (out of business), Incon (Out of business), and B&G are systems are all turbo kits I've always heard great things about. I have personally run Incon and currently am running HP Performance. They were both of excellent quality! I have heard horror stories about On3 systems, particularly the early ones. I would personally avoid them entirely. Some people claim they've done well with On3 stuff, but seeing is believing.
Groverdill would lose his ass selling his car at any market price, especially at the $15k being tossed around in here. That said, his is an extreme build with all aftermarket components. Whenever you get beyond the ~500rwhp range on foxes, everything changes and costs go up tremendously, because now you have to get away entirely from the stock fuel system, drivetrain, and electronics. If you stay south of 500, you can find some cars in the range you're discussing. I bought my incon turbo car in 2004 for $11k. It had a GT40 build and a stock cam and made 420 to the wheels on 10 psi. It ran beautifully and I was very happy with it. So, they are out there. Good luck!