What we just bought.
I found a 2002 KDX 220 in CycleTrader for $2500. I called the guy and it was about a 2.5 hour drive to see/get it. The guy came down to $2200 on the phone. When we got there, I looked it over and YES it had been ridden. If I had seen more pics, I probably wouldn't have even gone. Anyway, it was complete, had a few extras: pipe, silencer, bars, guards, skid, and new Michelin tires. It needed sprockets in the worst way. Anyway, the guy said it had ALL the bearings replaced... So, while I had the bike on the stand that I brought with me, I found the rear wheel bearings to be shot, but couldn't get any play in the shock link. I was nursing a hurt back so I didn't "get on it" and wanted to believe the guy was telling the truth. When we got it home, I found the lower shock bearing to be shot, and none of the bearings replaced... at least from what I could tell. Supposedly, it has a new top end - it does have good compression and runs well.
So far our list of replacements have been/will be: all the bearings in/for the shock link, swing arm bearings (not shot yet, but they will be replaced), rear wheel bearings, and some plastic and graphics for looks. Bottom line: We paid $2050 for the bike. Not too bad, but I think I would have rather paid more and gotten a bike with less ride time on it.