Hi, joe,
If I missed out on welcoming you, here is my "howdy"!
I have been checking RV sales online for over a year and it seems that the 'snowbird' states are the places where I see the most RVs for sale, and at better prices. Those states being AZ, TX and FL, with TX and AZ seeming to have a bit more.
Now as to your other questions, my thought is that it's like anything else. You take your chances when buying used. I would, however, check into what manufacturers have gone/are going out of business. Don't rely on a saleperson to give you this info, either. Once a manufaturer goes out of business, all warrantees are no longer valid. You would have to buy an extended warranty from another source, like Good Sam's.
Just my 2 cents worth!

Lenora & Choco
"Sometimes I wonder. How did I get to be so old? Then I remember, Oh yeah, by the Grace of God."