Mike,
Amigadave is right. A good, clean 3000 or 4000 is not cheap. Two years ago I picked up a 3000 for $50 and it came fully loaded along with a a3640. That was off Ebay! Now I'm seeing them priced $80 and up, and not always fully loaded. I tried to get a 4000 cheap for a year before finally paying $150 last October for one from somebody from the
comp.sys.amiga.marketplace newsgroup. (Google doesn't always seem to refresh the messages often, so you might want to try your ISP's group server for that newsgroup). Another source to check is
Amibench. Most of the buyers/sellers are from Europe, but there are quite a few in the US on there now and then as well. Of course, there's always Ebay ... if you're patient and don't mind loosing many an auction to finally win one at your desired price. Expanding your search beyond your 60 miles will also help you in your search. Good luck, and with either system you'll be very happy.