I would buy the trailer. You have a tractor, so it will get some use in the winter (it needs to be worked occasionally too). Much cheaper in the long run, you get over your separation anxiety sooner (and some cash) versus the slow deterioration (and maintenance costs & hassle) of its aging. The trailer will not cost much at all in the same time frame.
I do have a contra thought: As time goes by, used pickups will start to get scarce, driving prices up on decent ones. So next spring (especially when graduation is getting near) will be a great time to sell. But -- no ac, sell before it gets warm. Things like time will be part of what gets the economy going (my brother is finally seeing customers order bits/dies as they finally are running out of stock -- used equipment will see the same trends).
I do have a contra thought: As time goes by, used pickups will start to get scarce, driving prices up on decent ones. So next spring (especially when graduation is getting near) will be a great time to sell. But -- no ac, sell before it gets warm. Things like time will be part of what gets the economy going (my brother is finally seeing customers order bits/dies as they finally are running out of stock -- used equipment will see the same trends).