 A fill-up is a bit more costly, for the most part because of higher oil prices. AAA's fuel price report says the nation's average price for a gallon of regular rose about 5 cents over the seven-day period that ended yesterday. At $3.49, it's still 9 cents less than a year ago. AAA says Oklahoma had the fourth lowest price for regular in the nation on Monday at $3.06 a gallon. That's a rise of 6 cents from a week ago.