So this is at a dealership? Some of the main things to look for are oil leaks on the engine and front & rear diffs, loose suspension parts, any noises while idling and riding and make sure the engine doesn't smoke. Also make sure it shifts into the gears correctly without any grinding or noises. Then take it for a good beat run just to make sure there isn't something on the verge of failing. I own a 02 AC 500 auto and I bought it 2 1/2 years ago for $370 but it was pretty beat up. I basically did a full restoration, rebuilding the top end and adding power mods. I'm fully in it now for $1700 and its a nice reliable quick atv.