Gas Prices Down This Week says that the average price for gasoline in Maine has fallen 5.4 cents per gallon in the past week.As of Sunday, the average price of a gallon of regular gas is $2.84. That price is comparable to the national average of $2.80, which is 6.8 cents lower than last weeks numbers. While Sunday’s average price in Maine has fallen in the last week, it’s still 40.9 cents per gallon higher than the same day one year ago.