A lot of tractors have two big batteries that are not cheap either. Then there can be fuel related problems. You sure can throw a lot of money to try and fix that also. I always wanted to buy and restore a couple of tractors like my dad had when I was little, but it is not going to happen. I looked for a while for a Ford Major Diesel and a Massey 65 diesel with power steering to restore. I figured real quick I would easily get more in them than they would be worth. Parts are way to high.
I attended a couple pretty large machinery auctions recently and tractors went pretty low I thought, but just a few problems and you have a lot of money in them. If they were low hours and good shape they sold well.