A little higher than $20,000, but Keystone Outback is pretty good. But they average (MSRP) around $35,000. Outback (at least use to) use real wood cabinets, not composite or saw dust glued sides and doors covered with self-sticking shelf paper. Construction is all aluminum with foam board between for insulation. All the appliance are standard RV appliances though. But, for longevity, my Outback has been the best so far. They have walkable roofs, porcelain toilets, standard sink faucets, not the plastic RV types. I think Outback is one step above the rest of the Keystone brands. But, they are more than $20,000 too.
As with any brand, diligent maintenance and upkeep are key to keeping any of them in great shape! If you just use it and forget it, any RV will be junk in 6 months.
RV ownership is a lot like having a new baby. They take constant attention and money as long as you own them. Otherwise, like kids left unattended, they become derelicts very fast. That's why RV ownership is called "a lifestyle". An RV dominates your entire world (that is if you want to keep them in great shape for longevity).