Take it to the dealer that offered you $5k dump it off, grab your check and run like hell...RV's in general are complete money pits, they're ridiculously over-priced for no more than what they are, most times 2x2 framed if you are lucky and a lot of it is only 1x crap and the cheapest the manufacturer could find. If you gotta move it if it were me I'd move it once and that would be to the nearest dealership to sell it to them. RV's depreciate in value faster than a new car off the lot. Most banks won't loan that kind of money on a trailer that old and like you are thinking, who's got that kind of money for something that old.
Most people that can afford an RV are going to buy a new one, unless its someone in an emergency and just needs it to live in for some reason and doesn't have time or money to deal with a dealership.
Toy haulers are heavy, so that limits your buying group too. Dealership dump off sounds like a great way to go, and if that's a $5k don't care what shape its in deal I'd jump on it.