I'd say that TM was around $1000 new, so if everything on it works, it's a score. You can check them out at MinnKota's website.
Does the TM come with the cabled foot pedal or the wireless keyfob controller? One of those 2 items is required to run the TM. I prefer the key fob as I can go anywhere in the boat and even use it while fighting a fish when solo fishing,,, and not be tied to the foot pedal's location. I don't have the AP feature on my TM, but that will come in handy maintaining course.
Unless you can verify everything works on the TM I wouldn't look at as a $1000 TM. Heck, being used I would consider it a $500 TM if everything works, less if parts are missing or it can't be tested. I have heard of the compass unit having issues on some of them, the power board could be fried, or there could be motor issues. I doubt this is the case as MK TM's are pretty reliable, but it's something to consider as the boards do not come cheap, same for the foot pedal and keyfob controller.