the price of gasoline varies from area to area due to a number of factors. First and foremost, gasoline is a commodity. The price varies according to the price on the commodities market, which can vary greatly day to day.

The second major factor is the delivery zone. The main factor here is the distance from the pipeline terminal that the gasoline is coming from.

The third varying factor is state taxes. For instance, in Mass the gas tax is a fixed rate, (x number of cents per gallon), while in NY it varies, as it is a percentage of the purchase price, just like a sales tax.

Federal taxes are fixed.

Only after all those factors are taken in does the station owner affect the price, and they tend (with major exceptions) to keep the price of gas as low as a profit margin would allow, because they want you to come in to the store for coffee, etc. (the exception would be the fool in Binghamton who is 40-50 cents higher than his competition across the street)