This term, I've been experimenting with buying as many textbooks as I can used, through Amazon Marketplace sellers; there's some fantastic deals to be had even compared to the used price of the student federation bookstore, especially in denser tomes. It helps, though, to order far in advance, as some sellers can take two to three weeks to ship.
At the other end of the scale, however, there's sometimes not a great deal of advantage in going this route. On Monday night, I ordered Walk Two Moons
from one such seller; it's one of the few texts I needed for Children's Lit that either I didn't have already, or couldn't just load the public-domain ebook thereof on my PDA. The price was $2.50 Canadian, plus $6.49 shipping. Amazon's own price is $7.99, true, but apparently it's a special order title for them, as the shipping date is 4 to 6 weeks. As I'll need to have read the book by midterms, that didn't help much, so I decided $8.99 total seemed fair. (And worth it, rather than waste time hiking over to Benjamin Books, the tiny and inconvenient extra-university store where the prof had actually ordered the title.)
I received the book in today's mail. Entirely by accident, I'd managed to randomly pick a seller in Ottawa, and intra-city mail is only one day. I do feel a bit silly having paid so much for shipping, considering that, however. The moral, I suppose, is that it seems any assigned text under $40 or so won't be available for much of a discount used; above that - such as for this
$63, 1200-page leviathan, which I got for $18 including shipping - it's very much worth it.