I hear you, it took me 3-4 months of looking for a used trailer, I needed a bigger one. Then, my neighbor sold me his, he bought it new, left the county 3 times, 8x20' 2500 bucks, smoking deal!!
I've never seen anything on Wheels APPRECIATE in value.
I shopped around before I bought mine, 7x16', dual 3500 axel, ramp and side door, electric brakes with 3/4 ply flooring.
I paid less than most people are asking for a used one with their logo on it, that I'd have to peel off, and repaint so you don't see "get er dun construction" faded on the side of it.
For some reason, people keep listing $3000 16' used trailers, and for some reason, people buy them.