Iowa drivers are paying a little less for gas compared to a week ago. The average price for a gallon of regular unleaded in Iowa is $2.51, four cents lower than last week. Triple A says Cedar Rapids posts the lowest prices statewide at $2.43 a gallon. Prices are highest in Des Moines at $2.62 a gallon. The average cost for a gallon of regular unleaded nationwide is $2.64.