I actually checked Amazon for you. Even the used copies seem to start at $13! If you're going to order it online, Wal-mart is actually cheaper, $11.50 and it would be new. I wonder what their in-store price is.
Many people disliked Breaking Dawn because of some of the concepts in it (and it was too adult for some teens), so there are probably people out there willing to sell or swap their copy. Maybe put a note or poster up at your community center or church bulletin board or one at the laundromat or supermarket, wherever there's a bulletin board or kiosk.