I don't exactly fit your criteria, but I used to manage a fleet of rental class C's and A's for a dealership, which we sold off when they hit about 35k miles. (sometimes up to 45K)
A few things about rentals...
Be careful who you buy it from... An independent dealer would likely be better. BEware of units sold from big national operations (I won;t name them) they often will take the coach from an older unit and graft it to a new chassis and viola, the 2007 with 75k miles, is now a 2010 with 10k... but the "house" is beat.
Typically, rental fleets are the lowest trim line. In fact many are special trim lines and nameplates made specificaly for Rental... ie the "Pathfinder" Class A Cochmen motorhomes from the early 2000s.
On the other hand, if it is a reputable dealer, the motorhome will have gotten regular service, and will not suffer from the problems that come from sitting idle too long.
If you are careful you can find some great deals in ex rentals.
