To a starving student, even a older edition book is better than spending 100-200 dollars on a new one. I remember it would be like 500-800 dollars on a new textbook every semester.
UBC bookstore might buy your book back.
UBC Bookstore - http://www.bookstore.ubc.ca/
I tried looking up some of my old books, they didn't have them listed.
Recycling would be the easiest option.