Well with the cheap new motors out there the used market for motors is not hot. Plus who knows what kind of shape this motor is really in.
I like the statement that it ran 4 years ago. That is kind of like guy selling tractors that say it run when it was parked. Now maybe that was 30 years ago and it really broke down right where it is setting.
You might get $50-100 if someone puts much value on the hydraulic pump that is on it. The pump and mount is worth as much as the engine.