It's tough to guage very much from those snapshots, but for $40 it would be pretty hard to go wrong. If the plane is flyable and the engine runs, it's well worth $40. If there are servos installed with a receiver and flight pack battery, then it's even more worth it.

On the other hand, if it's a busted up old airframe with no servos or radio equipment, and there's an old glow engine with rusted out bearings on the nose, you'd be better off keeping your $40 in your wallet.