There is competition in the gas refiners market, but that isn't the reason prices are above 3 bucks. The problem is there is no competition in the oil pumpers market. OPEC controls the market. Oil isn't selling at 75 bucks because Exxon said so its because OPEC doesn't produce at 100% of there capacity.
So when Exxon makes a dime a gallon off your three bucks, Saudi Arabia makes a buck and a half off it.
Gas hits 1.48 in Red China today.
http://money.cnn.com/pf/features/lists/global_gasprices/price.html