C-Store Decisions: The average price of gasoline in Iowa dropped 7 cents this week compared with a week ago, according to AAA. That was among the top 10 price declines nationally. The U.S. average price of gasoline, at $2.38, was down 5 cents from a week ago, 5 cents from a month ago and 9 cents from a year ago. The crude oil market has plunged in response to a lack of agreement between OPEC and non-OPEC countries to cut production.