I have 2 of the exact same trailers... super heavy duty units, but haven't found much of a resale market, although I didn't try very hard either.
The air / hydraulic brakes and the lunette height are a bit of a down side, but I bet there is someone who could use it off-road, behind a tractor etc. maybe to haul logs out of the woods??
Unfortunately it doesn't have a lot of usable space for such a heavy trailer, but maybe there is a different use out there somewhere....