Saving money on books

As I perused the website at Cheesemaking.com, I found a book I really wanted.  Unfortunately, I felt it was a little high-priced for a paperback book.  Any time I find myself in this situation, I check on Half.com, a division of Ebay.  90% of the time, I'm in luck, as I was with this book.  Unlike Ebay, there's no bidding.  The worst thing about this is that the postage often costs more than the book I'm buying, but I still save lots of money.  
The book is $16.95 new; I got it for $2.96 plus $3.49 shipping.  The seller listed it as being in satisfactory condition, but I would say it's in "like new" condition.  I was pretty lucky, because today there are no copies of this particular book for sale there.  (After doing this entry, I checked Amazon.com and found many copies of the book there for under $4.)  
Half.com is especially helpful if you are looking for an old, out-of-print book.  Those are often the cheapest, because there's no demand for them.  If you are as old as I am, you might remember Gale Storm:  My Little Margie and Oh Suzanna were TV shows in which she starred; she also had a couple of successful recordings.  One time I found out she had written a book in the 80's and I wanted to read it.  Sure enough, there it was on Half.com.  I see there's a copy of it there right now for 75 cents.  
Just thought I would throw that out there.  It's one of the two best places to save money on books; the other is Amazon.com, which right now has a seller with an old copy of Gale Storm's book for a penny, plus $3.99 shipping.  Not that any of my readers are probably interested in that particular book.    
Maybe everybody already knew about these resources, but it never hurts to pass a little information along.