I'm sure you've considered this, but in case you haven't - do you actually need a trailer to move your tractor?
You most likely do if you're planning on keeping it in one place and using it elsewhere, but many people don't ever need to move their tractor, barring exceptional circumstances such as needing to take it to the dealer. Your dealer delivers, and assuming you're able to do the general maintenance yourself (grease, oil & filters), it could be years before you need to take the tractor somewhere (I'm at 6 years of "I need a trailer" but still haven't).
Considering the high price of trailers, occasionally renting one may be sufficient, or just having the dealer pick it up as you mention, could probably be done 20 times without getting to the price of a new trailer sufficient for the tractor (let alone paying for another truck).
[Also: if you're able to trailer your tractor, you're able to help people on their land with your tractor. If you can't, you can't. This may or may not be a good thing.]