Those pics are not great, but it looks like a fairly low play game just looking at the inlane drops. The flipper button protectors were not standard, ask to see what's underneath, it's just a couple of screws to get them off. I'd like to see the shooter lane, front of the cabinet, itchy and scratchy hole. Ask when the batteries were last changed.
It needs a good cleaning, you can see the ball trail mark coming out of the shooter lane, very common on this game. Probably needs new rubber and a shop job, which is very easy on this game.
Nice tspp games are going for $5-6k. This one is likely worth $4500$-5k. No way $3500.