One of the guys on the Woodnet forum recommended www.hamiltonbooks.com as a good source for woodworking books, so I gave them a try.
I mailed (snail mail) my order on 6/19 and received it today, 6/30. Ten woodworking books for a total of $48 including shipping. Most were advertised as "shopworn", but they look as good as new to me.
In the past I have recommended the public library to guys looking for books, but at these prices I like having the books to refer to at will.
They also have books on many other subjects. I recommend checking them out.
PS I have no vested interest in Hamilton Books in any way!