I have managed to get the price down, to 18 $ ( 13 €)! Shipping 14 $ to Europe, and 21 $ to the rest of the world. Buy it here.
EDIT: If you feel the shipping is too expensive for you ( it is the price the postoffice takes and I am sorry I cannot send it for less ), you can buy the file for 8$, and print it yourself! Send me an email to buy the file!