If something seems like a great deal (or too good to be true), and you're interested, you better say you'll take it for their asking price and drop what you're doing (job, etc..) immediately and drive to pick it up with cash in hand.
I've bought a few games where I knew the condition could go either way, but based on what I knew, I decided that it was worth committing and just going to get it. One was a 720, for a fair, going rate price, and the game turned out to be in better shape than I expected.
Another was an ad for a Ms Pac for like $100. I knew it could be a parts game or a cocktail that I didn't really want, but I told the guy I'd take it, left work immediately, and drove as fast as I could to get it. It turned out to be a playing blind, upright cabinet, faded with a hasp bar, but complete with the original manual package stapled inside. The paint looks like ass, but aside from that and the hasp holes, it's a perfect restoration candidate, unrestored, and everything original like it left the factory, plywood cab, etc.. A flyback, HOT, and cap kit fixed it, so it was a great deal to me. If I'd hesitated I probably would have missed it.