I hate to burst your bubble but a dump trailer will put more PSI on your driveway than a dual wheel dump. Narrow tires and plenty of weight right over them leaves tracks in hard pack.
As for used; I’m considering selling or trading mine on a new one. If I can’t get 60% of new I’ll keep it and sandblast and paint it. If I were buying used I’d expect what I bought to be ready to work. Tires, brakes, lights, hydraulics, and battery all good. Then I’d take it for a ride, checking that it trailed well and I’d measure wheelbase side to side to check for worn or bent suspension. These things are prone to being ridden hard and put away wet. Deferred maintenance generally means it’s in worse shape than you think.
As for used; I’m considering selling or trading mine on a new one. If I can’t get 60% of new I’ll keep it and sandblast and paint it. If I were buying used I’d expect what I bought to be ready to work. Tires, brakes, lights, hydraulics, and battery all good. Then I’d take it for a ride, checking that it trailed well and I’d measure wheelbase side to side to check for worn or bent suspension. These things are prone to being ridden hard and put away wet. Deferred maintenance generally means it’s in worse shape than you think.