In Canada there is a grid, and the affluence of each grid impacts the price of gas sold in that grid. You can have swings of 20¢/L from one side of the tracks t

In Canada there is a grid, and the affluence of each grid impacts the price of gas sold in that grid. You can have swings of 20¢/L from one side of the tracks to the other - all sold by the same chain, fueled by the same trucks equidistant from the depot.