Iowans saw costs rise at the pump over the last week, but gasoline prices still remain well below where they were a year ago, according to the Iowa Department of Agriculture and Land Stewardship (IDALS) and AAA-Iowa. As of Wednesday, Jan. 28, the average price for a gallon of regular unleaded gasoline in the state was $2.55, up eight cents on the week and 39 cents below prices from a year ago. The national average for gasoline on Wednesday was up five cents to $2.88 per gallon. Iowa retail diesel prices climbed eight cents to a statewide average of $3.40 per gallon, just two cents below prices from a year ago. The national average for diesel on Wednesday stood at $3.60 per gallon.