All of the above books can also be purchased at major US bookstores (Barnes and Nobles, Amazon, etc) I usually purchase the books and have them mailed to my house. Check the company websites for availability. Another website you might want to check out is called Half.com. They have used textbooks as well as new ones available for purchase.
The only downside to these websites is that you have to wait some time for the books to be sent to your house.