The statewide average for a gallon of regular unleaded gas in New Mexico dropped slightly over the last week. It now costs an average of $3.48, according to the AAA New Mexico Weekend Gas Watch. That price is one cent less than one week ago and 25 cents less than the national average which is now $3.73. Of the major metropolitan areas surveyed, drivers in Las Cruces are paying the most on average at $3.51 and drivers in Santa Fe are paying the least at $3.40.