There are better opinions out their with diesel owners, whether pick ups or RV but if you are comparing a diesel PU to a gas class A I would think your maintenance costs would be more with the TT/5er set up. But no matter how you look at the maintenance costs, any way you look at the comparisons shouldn't be that much of an issue, barring break down and major repair which is a remote possibility at best, there are other considerations more important when considering TV and tow behind vs. driven class A's. If you are a pick up type of person(s) then there are some great floor plan options and available living space that 5er's offer over A's. But do you want to drive a large PU around town when site seeing areas you traveled to? I don't see any comparison of a travel trailer to a fifth wheel or class A when it comes to quality of components, especially interior cabinets and finishing's. They are made to be more light weight for ease of towing and to provide a wider range of tow vehicles that can tow them. With a class A you will be towing a car, either on a dolly or four down if you want to have your own transportation with you. Some folks will use scooters on some type of hitch mount rack or rent cars in towns they are visiting. In my opinion class A's, especially diesels, offer the best of interior accoutrements such as all wood cabinets, Corian counters, tile floors, dual pane frameless windows and more. All of these things are more important than the maintenance issue in question.