To me a "quality" built coach is one that performs as it was advertised. In other words, it doesn't matter if it is solid wood cabinets or particle board cabinets, I don't expect the particle board cabinets to fall off of the wall because they are a less expensive cabinet.
I can accept a plastic faucet, instead of a solid gold faucet, if it works like it is supposed to work.
I don't care if I have the cheapest furnace, AC unit, or water heater, or the most expensive, I expect them all to work as designed.
Electrical is electrical and plumbing is plumbing, I don't expect plumbing leaks or electrical problems, regardless of what they are connected to.
People know the difference between glitz and basic. They know the difference between leather and vinyl. They know the difference between tile floor and linoleum. What they want is something that works when they drive it off the lot and continues to be trouble free for a period of time. They don't want something that breaks down as soon as they get 500 miles away from the dealer.
A manufacturer can save money on materials, and most buyers can deal with that. What buyers shouldn't have to accept is POOR installation of the materials used which result in numerous problems that have nothing to do with the cost of those materials.