Seems a little high to me too. But it depends on the market. I'd say about $5000 less would be more reasonable. Does it have something expensive like hydraulic levelers, or specialized suspension besides the new tires? Does it have extra or AGM house batteries and a solar array and inverter? Does it have a fantastic temperature controlled vent fan? These might add to the bottom line but if it is stock, that is not something to pay more for low mileage. If you do think you like it and want to deal, would he let you get it leak tested? An RV that old without leaks is desirable.