Maine is usually on the higher side of prices, generally speaking. This is a gross generalization based on the general trends when prices are called out on various tractors.
So it sounds like it was actually used. That's OK. If it was cared for, that shouldn't matter one bit.
I'd look at the little white transmission cooling fan underneath. If all the blades are busted on it and the owner didn't replace it, then I'd use that as an indication of just HOW it was used and how much the owner worried about fixing it.
You can get a simliar indication by the boots on the steering knuckles.
I'm not a fan of storing these things outside. Folks say that it isn't any different than a car, but a car doesn't have all the exposed hoses, exposed seat, and other things that these tractors have. I know farmers have been storing their machines outside as long as there have been farms and tractors, but those were the days before cushined seats, fuel injection, and computers.
Doesn't make it a bad buy, but I'd take it down a notch for it being outside in the cold and snow for years.
Other opinons will roll in. Just wanted to get some facts to help others out.