I just pull up to the local airport in a junker, but street legal pickup that I keep a internally clean 55 gal barrel strapped up and buy what I can afford. Once I established an initial relationship at the airport, it's been easy, they even accept cash. If they land and fuel Lear jets, look for a smaller drome. If I lived in the King Corn Belt, I would probably buy even more, their pump gas really sucks.