$15,000 will buy you one fairly decent with a few niggles. $17,000 should buy you one with no hassles. Look for if it has had the belts changed, regular services/oil changes, good gearbox, no rattles etc etc. Basically look at all the internals first and foremost. Your priority should be the overall condition of the car. Not exhaust, rims etc. If I could go back I would buy one that had already been owned and driven by someone who did all the regular maintenance. It's so much less of a hassle. When I bought mine (which I am the first owner in Aus) I had a full tune, timing belt changed, new Iridium spark plugs installed, compression test, all fluids replaced with high quality products, an alarm that complies with insurance (most alarms don't which void your warranty if broken into). I spent around $2,000 on all this including labour. Then I had insurance! But my R33 runs like a dream and I treat it well. I see a lot of shitty R33's going around that look neglected and don't sound so good. So it's best to search around until the right one comes up.