School Books

Hello, I have been studying abroad in Egypt this academic year and I have around 15 kg worth of books that I'd like to ship back home to the states ahead of me. I'm living in Cairo right now and would like to send my books to Edmonds, WA (zip code 98026). I'm looking for the most affordable mode. So far I've only found prices between $250-$275 which is a lot of money. I'd appreciate a quick response. Ideally, I'd like to send the books no later than this Saturday, April 8th. Thanks.