I drive 5000 miles a year. That is close to 800 gallons of fuel. I use Pilot and Flying-J using a Good Sam Discount Card. So if I could find deisel at $.25 less, that is only a saving of $160.00 for the year (with the $.05 Good Sam discount.
A very small price to pay for the convenience, easy access, high volume pumps, not having to go in to prepay before I can pump fuel, not having to repeatedly reset the pump when it shuts off at $75.00, etc. Plus they always have a well stocked store to pick up essentials if needed.