Here is the site that you input your books ISBN in order to get a quote:
http://sellmytextbooks.org/members/1...cfm?index=SELL
Also, just to clarify, the McMaster Campus Store DOES NOT buy your books back. Buyback is done by a completely separate company that is used by most universities in Canada. The quotes are given by that company and those that you are selling your books to do not work for the campus store.