Like myself when I purchased my first used class A I concentrated to much on mileage. In my opinion is to wary of a coach that has been left idle for long periods of time. Like a boat in my opinion the worst thing is not use them. I would first concentrate on floor plans and other things. Mileage is a consideration but shouldn't be the top priority. I have a DP but a budget of $40,000 I would recommend concentrating on a gas powered coach as you will get a better floor plan than an older DP without or no slides. JMHO good luck and enjoy!:)