bookstore will always buyback ur book, but not at reasonable prices. you get the most money early in finals week.
http://www.bookstore.csupomona.edu/b...V1QM7ELPLTDKUB
"All books bought during the regular quarter are purchased at prevailing wholesale prices as established by national used book companies. Current editions of textbooks typically get from 10-25% of the new retail price, and trade books and study guides usually get from $.50- $5.00"