The Achilles heel for many towables is the frame. That frame for most of them is a Lippert frame. I have one under my Alpenlite which in the last 5 years has been in every state & dragged to Alaska too.
Over the years I have made a number of upgrades to that Lippert frame. I have an airbag hitch, the Equaflex centerpoint suspension with the wetbolts, rebuilt the frame in the area of each spring hanger, new shocks & this year new springs, going from a 6 leaf stack to a 7 leaf stack.
When surveying any trailer get underneath it to have a look at the most important frame before going inside to see all of the glitz & fizz.
Inside check on quality of fittings such as drawer slides & light fixtures. That should tell if the builder has tried to cut corners to save building costs.