You should check out "The Casual Courier" to send your books internationally: www.casualcourier.com
On the site, you'll be able to find an everyday traveler to deliver your books at a fraction of the cost of traditional delivery.
Their philosophy is: "You're going anyway -- so, why not take a package with you and make some extra money!"
Registration is free and easy. You only pay a small fee ($0.99 USD) when you choose to purchase the contact information of the courier that agrees to take your books.
Good luck!
www.casualcourier.com