Spending thousands on fuel and wear on the truck to avoid sales taxes may be a good move as you get a trip in the bargain. The downside is that if the factory screwed anything up what are you going to do if you notice when you first arrive?
Someone mentioned the dollar savings with a used camper and to that I would add that the first owner had to work through any problems with the camper as it arrived from the factory. I bought a very lightly used 3-year old Lance camper and saved 50% compared to buying one new and that is not also adding in the sales tax, dealer prep, freight or any other charges incurred when buying new.