gasoline prices

i am not a conspiraty theorist, but something is definitly up with gas prices. they blame it on the price of barrels of crude oil, but i think that theory is suspect for a couple of reasons. number one: the price of gasoline varies according to the location of the gas station. i can travel to 4-5 different towns within the space of an hour and the price will vary as much as 10 cents a gallon from one town to the next. if the problem is the price of barrels of crude, all gas stations would sell it for approximately the same price give or take a couple of cents. reason number two: prices of other oil products and by products have not gone up proportionately. motor oil, transmission fluid, brake fluid, even by products like plastic haven't increased the same rate as gasoline prices. if the reason for raising gas prices was the price of the source shouldn't all oil related products go up at the same rate? no, something else is the reason. i can only surmise, but i bet it has something to do with greed. who's greed, i can't say. i won't blame it on the president. there are enough liberals out there to do that and i don't really think he is that evil. or greedy. if it was opec that is making the prices go up, then all oil related products would go up too, after all, why waste your chance to make even bigger profits? i don't know. any one have any theories? let's hear them.