ST. PAUL, Minn. (AP) - Just in time for the Memorial Day weekend and as the cost of gasoline continues to climb, Minnesota is cracking down on service stations over gas prices. Prices that are too low, that is. A law the state adopted in 2001 in an effort to protect small service-station businesses prohibits gas stations from selling gas without taking a minimum profit. These days, they must charge at least 8 cents per gallon, plus taxes, more than they paid for it.