Great topic! I love the ending picture, its amazing how creative some people were. Some more info on it would be nice if you have any.
I was a little surprise to see that a member from Arizona didn't know where to look for good used RV's. I would have thought that they last better in AZ than anywhere. But, considering that AZ is a popular RV full-timer / retirement location, I suppose it is also a final destination for many RVs and there are lots of tired old units.
I have been looking around at < $50k class A RVs. Some clues to good ones (I think) are private seller, picture of storage garage (or barn) in the background, service records, etc.). But, the problem I have is linking mileage to amount of use. A unit that was used full-time may have low miles, but it could still be pretty tired.
I have also met people who run the generator all-the-time so that they always have 110v electricity. They reason that the main engine burns so much fuel that running the generator doesn't make much difference. Because of this, generator hours is not a good indicator of amount of use.
