i think you're missing the point, people spend $15 all the time without thinking about it... hence my examples.
And yeah people do part with $15 on known entities in brainless ways. This is a new behavior though. This gas refueling scheme ain't gonna make sense to the vast majority of people, hence once again cue the Dana Carvey George Bush skit...."Not gonna do it."
Much fewer people will pay $15 to avoid 40 minutes of driving or waiting.