The taxes are what makes the difference. Take yesterday's closing price of $1.00, add the Fed tax of I think 18.4-cents, add your state tax, and a distribution fee, typically around a dime.
If you live within a few miles of a gasoline pipeline, you could subtract about 8-cents/gallon from that distribution cost. It's likley that either you're near a pipeline or the stations are selling at a loss to drive convenience business.
Did you guys see Flying J truck stops filed for Chapter 11? They're a pretty big player in that business.