If you're getting an RV to save money, you'll be disappointed.
No matter how you do the math, it usually does not add up.
Sure you may save some $ over a hotel compared to a campground. But that $15k you spent on the RV would sure buy a whole bunch of hotel rooms. There's the extra gas to get there, maintinence, and extra wear on the vehicle. Add in at least a few hundred $ for a hitch. Add in the cost of everything you need to stock the camper, I have thousands in just stuff for camping not including the camper.
You won't save money. Ever.
RVing however, at least for me, is more satisfying and rewarding than any hotel room. It's an experience that, while not for everybody, is absolutely fantastic.