 The average price of a gallon of gasoline in North Dakota went up nearly 10 cents per gallon last week. GasBuddy.com says the average price is now $3.29 a gallon. That's a nickel higher than a month ago, but 16 cents lower than a year ago. GasBuddy.com says the demand for gasoline over the Fourth of July holiday plus $80 per barrel oil price could mean slight increases.