Well Mazda only brought the third generation RX-7 here from 93-95, so that will help a little. Also, when you're searching, look for FD3S, that is the chassis code for the third generation model and it's primarily known by that or just FD, FD RX-7, etc. If you're looking on cars.com or autotrader or whatever, watch out for scammers. I bought mine 10 years ago and the first 3 I looked at were scams, saying they were in Romania or wherever. Sometimes you can find them on here or RX7club. I assume you want the car to be running, or does he want a project? If you get one without an engine and/or transmission, you could find a decent one for about $6k. These days you might actually be able to find a running one for that much. I got mine for $10k in 2004, and the prices seem to be about the same from what I can tell. There is also a thread on here about buying FDs, I'll see if I can find it.
http://rotarycarclub.com/rotary_foru...ght=buying+gen
Good luck with your search!