Agree, those first few years are the hardest. If you're only thinking of keeping a trailer for maybe 3 or 4 years, would strongly suggest you look at something already a couple of years old...the worst would be past.
So much depends, no only on brand, but on floorplan. While bunkhouses are very popular and lots of demand for nice, clean ones just a few years old, we would have zero interest in one. If you're buying with the resale in the back of your head, look at the appeal to a larger group of buyers. Try to stick with a more generally neutral interior and stay away from overkill on graphics. Look for something with a functional kitchen, nice bathroom with some storage, good exterior storage. Personal opinion is that I'd be more interested in a nice, gently used trailer with good quality basics than one with a bunch of glitz. And, yes, you have to get it at a good price in the first place to minimize the depreciation hit down the road. AND maintain it meticulously.