In the market today there are only a few refineries, so gasoline no matter the name brand on it comes from just a few refineries they all get girl gasoline from from the same refineries.
But where do they get boy gasoline?
The states make the most because of taxes. Some have fixed prices while others get a percentage. Gas stations will break down the cost and put it on the pump as they do not want their customers to blame them for the rise.
In California it is always the state that raises prices. I think they “collude” with the refineries.