Looks nicer than our 2006 LBZ. If I was closer, I'd be very interested at that price. That's very fair for a no rust truck if the head gaskets are sound, injector balance rates are within spec, no blowby, and trans holds power.
These trucks pull trailers effortlessly. Its what it was made to do. Ball in the bed doesn't mean much. I'd be more concerned about abuse if it had a lift, bigger tires, big exhaust, emissions components, removed, tuned, etc. At stock power and maintained the drivetrain likely has good miles left in it.