COLUMBIA, Mo. (KMIZ) Missouri drivers are getting a break at the pump, with gas down by 13-15 cents across all types, according to AAA. However, consumers could see higher grocery prices because of how expensive diesel is. "I think this is affecting all retail, not just grocery," CEO and president of the Midwest Retail and Grocery Alliance, Dan Shaul, said. "The cost of transportation is figured into everything from blue jeans to lead acid batte…