Mamapedia has a nice deal for a closeout book site: pay $15 and get $30 to spend at BookCloseouts.com! Shipping is $2.99 per shipment + $0.50 per item, and you can use the voucher value to cover the cost of shipping.
I did some looking around and they have a pretty wide selection of books that are pretty reasonably priced, especially with the voucher. I’m going to take a look at our history curriculum today and order some books that coincide with what we’re going to be studying. Go here to read more and get your BookCloseouts.com voucher!