Ask him how often he drained the water from the tank (if it was on a regular basis like once a month or week) then you in good shape if the price is right!
Josh
I bought a compressor for the same amount that appears to be about the same age and size. I was able to open up the drain plug on the one I bought so check out how much sediment had accumulated in the tank.
Looks like a very good deal if its in good shape. For $200 I don't think you could go wrong. If you get it and don't like it, I think you could sell it for $300+.