Square Enix released today the WORLD OF FINAL FANTASY Original Soundtrack in Japan which includes all the BGM tracks and theme songs of the game on 4 CDs.
The price of the soundtrack album is 3500 Yen + tax. Square Enix already opened the official website of the album where you can find it in here with the official tracklist: http://www.square-enix.co.jp/music/sem/page/woff/