If I was going to buy a rebuilt motor I would ask to see a list or work order on what type of work was done and why did a 10 year old motor need to be rebuilt? there are a ton of 20 year old motors out there that haven't been rebuilt so that is one thing that stands out, the other motor for a grand less well a Merc controll box with cables could run up-wards of 200-300 dollars plus the cost to de-rig/ rig your boat could get up to if not more than the rebuilt. If the rebuilt motor is a dealer ask if it has say like a 3 month 50/50 warranty if they rebuilt it , ( I Would ) but that way if something goes wrong then it wouldn't cost the full amount. Thats my best guess