I've noticed on the smaller lightweight trailers, that bunks use up a lot of the available weight capacity - sometimes leaving you only 400lbs for people, dogs and gear. If you don't need them, I would pass them by. I also think it's more important to get a rig that you're happy with, than worrying about re-sale value.
You'll get a lot of "go bigger" on this forum. But, for me, I have preferred the simplicity of the smaller rigs. I don't want to deal with slides, I don't want to have a combined length of 30+ feet, etc. My TT was 18.5 ft and my 2 large dogs and I fit fine (without having to convert the dinette - slept of the sofabed). My class C is 20.5ft bumper to bumper and fits us, a parrot, and an occasional friend without issue. In both rigs, I routinely have 3-4 persons inside chatting, eating, etc. and the critters. It is snug, but everyone is comfortable.