2wd or 4x4? Amenities? top type? These will be less important; however I'd say as a generalization that a 2wd fixed top with propane furnace will have considerably less value than a 4x4, penthouse, and Espar (diesel powered) furnace and coolant heaters.
You also have to ask what items are important to you? Diesels are great, but if you don't need or want a diesel then it shouldn't be high on the priority list. I'm probably jumping off into left field here but I just know how easy it is to get lusty after these rigs and start thinking irrationally.