The thing about higher priced, good quality RVs is that after a few years, they end up filtering down through the used market. Class "B" rigs tend to be this way because they don't tend not to turn into rotted powder unlike a number of other rigs.
The problem is that Americans don't really have a choice on the matter. When you go to a RV show, you get presented with TTs that are built almost identically (same rubber roof construction), and there might be a few features such as a bit more insulation or some accessories that differentiate them. However, things would be completely different at an RV show if some of the Aussie or European makers had products for sale. For example, trailers made using industrial strength epoxy as the main sealant of choice. Trailers with propane fuel cells so even if the sun isn't shining, the batteries are topped off and the refrigerator can be a compressor fridge without sacrificing boondocking ability.
If Americans were presented with something other than the usual cheap stuff, but products that would have a real resale value, I'm sure they would buy it. One can point to Airstream as an example of this, where the TT may cost 3-4 times as much as others, but people still buy Airstream just due to the name still.
I do think that a top tier name from Australia, Japan, or Europe that can import small RVs that are not too expensive, but have the amenities people look for, would do well. Since Westfalia is upfitting Ford Transits, I can see a spot for their upfits. For example, a Westfalia Club Joker on a Transit van, or a Westie Ford Nugget. Just the name would sell them.