The cost of a gallon of gas in Maine is following the national trend and remaining steady. Price-monitoring website MaineGasPrices.com reports Monday that the average retail price in Maine has risen less than a penny in the past week to an average of $3.49 per gallon. The price is based on a survey of more than 1,200 gas stations. The in-state price is a full quarter above the national average of $3.24 per gallon. Prices in Maine are about a dime lower than a month ago, but remain more than 16 cents higher than a year ago. A company analyst says prices are likely to follow the trend in recent years and jump after Christmas.