Comments have been made on most aspects of your question, and have been pretty close in their read on the question. One add on you may want to consider, all brands use basically the same appliances, plumbing fixtures, electrical components, and all brands will route the consumer back to those manufacturers for service issues. What does come down to the TT builder is the box itself. If you buy the biggest box you can for whatever price point, you will get the cheapest built box they could slap together for that size.
Find a floor plan you like, then start looking at different lines from the manufacturers, they will offer the same floorplan in several lines. Low end lines will be put together with the cheapest materials, higher end line will get (usually and hopefully) somewhat better construction materials. Sadly, while the materials may get better, they dont seem to add a whole lot more time for assembly so small details still get missed.
Mid grade product lines seem to be acceptable to most folks if you look at whats on the road and especially in the campgrounds with seasoned owners. Those that are on their third or fourth units dont usually have the cheaper lines, they know the cost will be more by the time they include repair cost.
