Where can you buy .hack//ZERO?

I am a huge .hack fan. .hack//ZERO is the novel that takes place right after the anime series .hack//SIGN. Though it was supposed to be a series, only one was released, vol. 1 Phantom Pain. It is only available in Japan and was never translated to another language. Yes I am aware that the novel will be in Japanese. I have been having trouble trying to find it due to searches being clogged by "hacker" sites and if anyone knows where I can obtain a copy I will be forever grateful. Btw, I have tried Japanese Ebay.