I usually buy my textbooks used through Amazon or Half.com or eBay but recently moved out of state and found the textbooks listed on my distance education course confusing -- it appeared to be some kind of bundle of books but didn't list the individual editions. So I opted to order the bundle directly through my college's textbook store and have them mail it out to me.
First, they sent me a noticed stating that because they were out of used copies of one of the textbooks in the bundle, they would have to send me a "new" copy and charge the additional cost for it. This bundle of books came out to nearly $150 -- and it turned out the "new" textbook was the 2007 edition of a book that already had a 2010 edition available. I really felt burned -- not only had they shipped me a 2007 version of a book that had had 2008, 2009, and 2010 edition available, but they charged me full price for the book -- and I've discovered that the book is often available (used) on Amazon for less than ONE DOLLAR (plus shipping; search for "Discovering Computers", the Shelly Cashman series).
The textbook industry and their relationships with colleges are due to die a slow (well, okay, make it quick) painful death. I'm all for making open and/or digital textbooks acceptable for the classroom.