Multiple Buyers. Who gets the RV?

Had a similar situation when I sold my pickup. Last summer I guess I didn't realize that used trucks were in such high demand. People falling over themselves to buy a 13 year old truck with a rusted frame and 250k miles. But I got about 20 calls within 2 hours of the listing. I just told everyone that called, "I have had a LOT of interest in it and I cannot keep track of every single person calling. The first person in my driveway that hands me cash gets it. And I will immediately take the ad down when that happens. " I didn't concern myself with how far folks were driving. I would have driven myself nuts trying to keep track of who was virtually next in line. And probably irritated a few of them in the process. I did try and be empathetic to folks that told me they were coming from any distance. I was honest and let them know I had a lot of people coming. If they called me back in a hour to see if I sold it I was happy to let them know to save a trip.