After more than a month of plummeting gas prices in Michigan, the cost for a gallon of unleaded is now holding steady for the past week and has even gone up in some parts of the state. The average price in Michigan is now $3.95 per gallon. Metro Detroit has seen prices go down by 2-cents from last week and is currently $3.99 per gallon. Traverse City has the most expensive gas at $4.27 a gallon. Locally, Port Huron area pumps are around $4.03 a gallon.