By the way, I have never seen video game OSTs sold in stores.
It does happen from time to time, at least in North America. Particularly when an OST is licensed for distribution by a publisher that is based in North America. This is called the "domestic" release of an import soundtrack. Often it will have different album art (with English text), and sometimes even a different tracklist.
But for something like MYTH, online will be the only option. tushantin, you have the internet, and therefore have a way to get the album.
Off the top of my head there will probably be at least five online retailers that will carry this album, all of which ship internationally.