The KA engines are known to take a lickin and keep on tickin. They are truck engines afterall.. My friends 89 240 is almost at the 300k mile mark. It runs fine still. If the previous owner(s) know how to maintain a car then the car should be fine.

As for that price, I'd offer him 15 or 16 for it. People were selling 240s for 2k several years ago. I'm sure the value has gone down since then.