Buying advice on 2000 400ex?

Im looking at a 2000 Honda 400ex and the guy wanted $2800 and I talked him down to $2000.It has nerf bars, white bros pipe, k&n air filter and itp ss wheels with holeshot tires 90% tread , he put a 250r rear end in it new carrier bearings and plus I get the stock rims and tires.He also maintained it changed oil regular after 3 or 4 rides and plastic is good but one small hairline crack. Is it worth? Can anyone tell me things I need to look at when buying one used?