Price of gas in Mexico

Very few gasolineras do not have 4% built-in "error" in their dispensers. Couple that with the fact you ain't gonna get official exchange rate cash dispensed at cajeros automaticos, your USA bank fee and suddenly all those careful price per gallon computations go up in esmoke. I allow six point five percent vigorish, therefore 106.5% of the dispenser price of combustible. Six point five percent added onto "$3.85 gallon" ain't peanuts.

If it comes out of your bank account to pay for the gas, it's part of the purchase price...