What is the best way to ship to an APO address in Japan?

I have a friend who is stationed at Misawa Air Force Base in Japan. He says that the need is great for the Japanese people for basic supplies such as diapers, socks, gloves, scarves, toothbrushes, etc. He is helping organize shipments of donations from his friends here in the U.S. The problem I am having is finding a reasonable way to ship it. A small box through the US Postal Service is $50 or more. The shipping would be more than the value of the things inside the box. Any ideas?