James Willman seems to be a nice enough guy: polite, good-humored and hard-working, pumping gas seven days a week at the Amerigo Gas Station in the tiny Big Sur town of Gorda, about 35 miles north of Cambria. But at least once a day, Willman said, someone pulls in and starts cursing him. “They say all kinds of stuff—‘You ought to be shot,’ or ‘Where’s your mask?’ ” Willman said. “I’m like, ‘Hey, I just work here.’ ” The reason for consumer hostility is that the station is serving up what might be the costliest gas in the land. This...