The average price per gallon is up to $4.36, according to Triple-A Michigan. In the past week the price went up 13 cents per gallon. Gas prices in Michigan are up 13 cents from a week ago. Most expensive gas price averages:Lansing ($4.43)Jackson ($4.43)Traverse City ($4.42)Least expensive gas price averages:Marquette ($4.15)Grand Rapids ($4.33)Metro Detroit ($4.34)At the close of Friday’s formal trading session, WTI rose $1.08 to settle at $84.67 a barrel. Compared to last week, Metro Detroit’s average daily gas price increased.