Somebody way up asked about unbudgeted repairs. That is in the nominal $1000 a year that I figure is reasonable to carry as a placeholder. Maintenance is a minor cost; I do my own oil changes and fluid swaps. Motorcraft 5w-20 and filters 2x a year from Walmart, plus 3 quarts of Rotella for the generator isn't even $100 a year, leaving $900 of monopoly money for other stuff. This is a newer (2011) Class C, so the E450 part is pretty easy and the house still holding up pretty good. I did have to do a silly repair/replacement this Summer: lost a clearance light lens in a storm, and the vendor had gone out-of-business. The front cap was molded with insets specifically for these lights. Had to go to way too much trouble to find another one to fit, order those and fab up a way to have them look like they were supposed to be there. Total cost of the bits and pieces: $100. The entire Saturday of install time? Priceless. I also installed a new pair of front shocks as I was wondering if the Bilsteins I had on there were getting soft, along with a road force balance of the front tires. The shocks (Monroe RV Magnums) were bought from Advance Auto with a big coupon discount (I want to say $80 total for the pair) and the special balancing was $40. So this year I'm at $320. Next Spring I'll be doing trans and diff fluid; that'll be $200 or so, and I need to replace the existing trailer hitch as this one is a bit suspect. $400 there for that. In 2018 I'll be due for tires at $1,000 +/- for the set, but that big expense has been more than amortized over the years. In 2015, the only repair I can recall was the glass jar on the water filter sheared off at the threads. The fix was from the Home Depot plumbing aisle just installing a piece of braided line with the appropriate connector ends. I think it was $8. Done on the fly as a bit of a quick fix as I found the problem during a quick dewinterization leaving for the Daytona Rolex 24 that afternoon before I hit the road.
Like I said, this unit for a RV was relatively cheap to buy and certainly on the "less expensive" side to own compared to many. It is also huge that one be mechanically inclined and have the ability to work on most chassis and house stuff. That makes the biggest difference in total cost of ownership.