The price difference is affected by local cost of operations more than anything. That's why you often see low prices 10+ miles away from metro areas. You are only looking at the wholesale cost.
Sure, I understand that but I'm referring to stations within one block and one is charging 10-20 cents more per gallon.
These are major brand stations also. In my area Exxon and Shell are usually more than Valero for example.
All these stations get supplied from the same pipeline.
WaWa is one that is always more than others right across the road.
Some people don't care about paying more for the same thing.
Some people are brand loyal and believe a certain brand of gas is better than others.