$10K says used, no matter what size.
I don't know how long Travel Lite has been around, I've not seen their products in this part of the country. In this size range, I would be looking at "Egg" trailers with molded shells, notably Casita in the southern midwest, Scamp in the northern midwest, Escape in the far west (although Escape is no longer manufacturing smaller models). The basic structural integrity of molded shell campers in these small sizes makes them more likely candidates for being sound even when well used, compared to anything assembled as a box.
There is actually a model called "EggCamper" being manufactured today (17 foot) but at $25,000 new it is out of your price range, and has not been around long enough to depreciate to $10K used.