There is NOT a good correlation between price and quality, even within a given manufacturer. Jayco has a dozen different "lines" of TT. The biggest difference are trim. Basic construction is the same.
Eggshell TT seem to be of better quality/durability, but they tend to be on the small side. The only "medium" size eggshell that I know of is made by Oliver, 23'6". Oliver probably has the best warranty in the business, unlimited on the outer fiberglass, 5 years on the chassis, 2 years on everything else (probably not the appliances).