Tuition, room and board is only the beginning. The cost of going off to college not only trumps annual K-12 expenditures by a long shot but will be up 33.8 percent from last year to an estimated $34.4 billion, according to a consumer survey released Tuesday. To outfit the average college freshman, parent and student will spend an average $1,151.68, based on a survey by BIGresearch for the National Retail Federation. About half of that ($540.35) will be on consumer electronics. It doesn’t get much better sophomore year. The average is $1,028.57 as many students leave the dorm for a first apartment and shell out for bedding and bookshelves. When the amount spent on college trappings is added to the $13.4 billion spent on the younger student population, the combined $47.8 billion makes back to school the second-largest shopping season behind the Christmas holiday, NRF said. “The spending power of college students is something that retailers are just beginning to grasp. And there is no sign that this market is slowing down,” said NRF president and chief executive Tracy Mullin. Many chains are turning their stores into back-to-college destinations. J.C. Penney Co., Sears, Roebuck and Co. and Wal-Mart Stores Inc. prominently push campus solutions on their Web sites.