I think one of the least likely areas of failure in a used RV that passes the initial smell test is the engine and chassis. You can have the engine and brakes checked by any mechanic for a reasonable fee and be pretty confident in their assessment.
You are much more likely to have house issues. Structural integrity is number one. Look for leaks and look for delamination if it is a fiberglass shell. I would look over the plumbing. I would be concerned the electronics are due to age out. It's not a lot of money, but retrofitting modern TVs and sound systems can be time consuming and tricky. A refrigerator failing is expensive as well. Be sure the heating and cooling is in working order. Good Luck.