Buying a Former Rental Class C. How many of us out there?

I wonder what kind of resale value a high mileage ex-rental will have when you want to sell it to the next buyer. Seems to me that there are a lot of gizmos in any rig that have limited useful life along with big ticket items like the roof A/C and fridge, awniing, tires, engine cooling system, brakes, transmission, suspension, etc. Expect to start spending some money on items as they reach around 7 years old. If you can fix or replace most things yourself that makes a difference.