If your a mechanic you might want to look at used in auction sites. You have to be able to figure out if the tractor was well maintained and if something is going to go wrong what it will cost YOU to fix it.I have heard about the need to be able to work on the Chinese tractors but Im a mechanic by trade so that doesn't bother me much. Parts sourcing does though. A lot of the horror stories I have seen online are a few years old and I had hoped things had gotten better.
Most dealers don't seem to keep a large parts inventory any more, they get them shipped in when needed and you pay for the shipping. Rather than drive 80 miles round trip to the closest dealer I just have them drop shipped straight to me.
That pretty much contradicts the idea that the dealer should be a significant part of the decision process. At that point, the brand strength becomes more important to long-term availability of parts.