It all is about trade-offs. I bought an entry level travel trailer new, knowing that it is the "runt of the litter", because it had no slide-outs, and I would have to learn electrical, plumbing, and other skills in order to keep it maintained.
However, if I were to recommend a quality trailer that is not going to leak, or rot into uselessness in five years, I would recommend a horse trailer manufacturer (Bloomer Trailers out of Salado is one place), and have them do the job right. Just the fact that they use a one piece aluminum roof over rubber and aluminum framing will extend the life of the trailer well past almost anything "mass-produced" today.
A friend of mine had a trailer done this way. It has little in the way of plumbing and electrical (mainly an A/C with a heat strip), but it has gone through ice storms and 110+ degree heat easily. The trailer isn't really cared for, so it shows how well built it is when it just sits for months unused, which is a testament to how well Pace American built things.