DULUTH, MN (KDAL) - Beginning on Friday, the entry fee for the 37th running of Grandma's Marathon increases to 95 dollars for the next two months.  Then the price goes to 110 dollars from April 1st until the end of May.  The race will be held on June 22nd and is limited to the first 10 thousand runners.   Meanwhile, registration for the 2013 Garry Bjorklund Half Marathon begins February 11th through the 22nd.  Of those registering during that period, 6300 will be chosen in a lottery to participate in the race.  Registration and more information can be found at GrandmasMarathon.com