When did the downturn start, 2008?
It seems like there could be a great number of age problems and old technology to overcome, in an RV that is more than 10 years old. I would probably narrow the search to something in the early 2000's.
I like the Roadtrek (big surprise). But for a B+, I think there may be better choices.
There are videos from a number of different RV builders, showing how their body structure is designed. I would review those videos, and choose the most sturdy build. I don't think Roadtrek has the strength (for the B+).
The Pleasure Way video shows the roof and wall structure of their class B+. It looks very stout.