When you spend more money, you are generally spending for a bigger unit, more option features, or upgrades to items like cabinetry, furniture, fixtures, flooring, countertops, etc. In most cases the assembly line quality is about the same. Unless you spend a lot more to buy a unit that is more custom made.
Knock on particle board, but I have never had any major warranty repairs in the 10 years I've owned TTs (I did have a warranty repair on a previous PU).
I think the key to TT ownership is having enough mechanical ability to repair the small things yourself - otherwise you are going to have your unit at the dealer or repair facility quite a few times. For instance, just knowing which screws to tighten (there are a zillion on a TT) on a regular basis will keep you out of some trouble. And many times it is the small things that creep up after the warranty is over.