The cost of a gallon of gas in Massachusetts has ticked up a penny in the past week. AAA Southern New England reports that self-serve, regular is up to an average of $3.44 per gallon. The current per-gallon price is 9 cents higher than a month ago and 4 cents higher than at the same time last year. The Massachusetts price is also 19 cents higher than the national average. AAA found self-serve, regular selling as low as $3.34 per gallon as high as $3.59.