I think I would buy a used on, or one that is not set up as a camper, and then convert it.
But why are the new ones so expensive and yet break down as much as they do? Two major reasons:
1. Expensive, because you make more money when you target your sales in the direction of the rich;
2. Break down, because many of the builders and sellers don't know what they are doing when they build. They have $$$ signs in their eyes. The wealthy can afford to take a loss if they aren't smart enough to do due diligence. And the poor might not be able to afford a lawyer.