I got it from the Anime lady at the county fair nearly 10 years ago. I also got the Vampire Hunter D soundtrack from her as well as a Misfits belt. I almost bought a 2pac watch with fake diamonds and all, sometimes I wish I did. She never came back after that year.
I went to an anime convention and didn't find as much as the poppiest J-rock, and you found the Guilty Gear Isuka soundtrack at a county fair. Life sucks.
I was looking for Galneryus, maybe some of that Japan-centric Eric Martin stuff, with a lot of luck that Siam Shade tribute album with Jani Lane singing One Third Emotion in English.
For the person who was looking for the soundtrack, if you don't mind MP3s, I think the soundtrack is included with Both X2#Reload and Isuka on Steam. I know GOG included the soundtracks. That's where I got the games before they got taken down from GOG. I still bought them on Steam, though, because I want Xrd on PC. With the final(?) edition of DOA5 coming to PC and yet another BlazBlue version coming to PC, the unlikeliest of PC fighting games, I'm voting with my dollar and picking up every Arc System Works game on PC no matter how old it is and supporting other fighters I want to play and hoping for the best.
BTW, you can also use the PS2 version of the game for the soundtrack. You can probably rip the songs with a ripping tool on your PC and get higher quality rips than the Steam/GOG MP3s would give you, too. I know I ripped the three Genki Hitomi songs from the PS2 version of Ferrari F355 Challenge a number of years ago, but I forget what tool I used. You can probably find information on it on Zophar's Domain.