The price of oil is determined by what the world is willing to pay for it, not where it came out of the ground.

Average driver uses 700 gallons per year. The cost of shipping oil from overseas amounts to about 3¢ per gallon equals a cost of $21 dollars annually. The cost of shipping goes up with an increase in the cost of oil

It may not seem like much but every one ¢ rise in the price of gas takes 1.4 billion out of the hands of consumers so shipping cost of oil is 4.2 billion at the current price of oil.

Here's the kicker, these consumption numbers don't include the prices of diesel which as you know is passed on in the price of goods. Nor do they include the price of Jet A. Have you seen what is happening to the price of Airline tickets? It also doesn't include fuel costs associated with the importation of goods.

So where it comes from does make some difference in price. I don't think it's an insignificant amount.

EDIT: I guess you would have to consider how domestic drilling would effect the percentage of imported oil which would make the impact of freight less than the numbers above. Too lazy to work through it again.