We purchased our 16 yr old motorhome about four years ago used. Now with 48,000 miles. Focused a lot on maintenance and will do tires this year and rear brakes. If I suspect something, I get it checked right away. No issues to date for our Ford 450. I look at an older RV as a hobby, knowing that there will be fix-it's along the way. Some of the work I can do, some I can't. My biggest worry is our long extended road trips and having mechanical problems. But that can happen with anything mode of transportation, a car, airplane, cruise ship etc.
I do wonder, do Class C's have more repairs or does a Class A if there is much difference at all. I know a Class A costs more to maintain.