Under a plan approved by the Board of Governors, come January, campuses in the University of North Carolina system must reduce textbook costs for their students. Students in large introductory courses will either be able to sell their books back to the schools at the end of the year or rent books for the course. Textbook costs at U-N-C schools usually add 800 to 12-hundred dollars a year to students' bills. A federal study says textbook costs nationally have nearly tripled from 1986 to 2004. A spokesman for the Association of American Publishers says the new U-N-C policy will NOT have much effect on publishers.