The cost of a gallon of gas in Maine has jumped nearly three cents in the past week. Price-monitoring website MaineGasPrices.com reports Monday that the average retail cost of a gallon of gas rose to $3.55. The price is based on a survey of more than 1,200 gas stations in the state. Even though the national average rose more than four cents in the same time span, the average price in Maine remains 24 cents higher per gallon. Current prices in Maine are just about the same as they were a year ago. A company analyst says prices are rising because this is traditionally refinery maintenance season, when production drops.