
The closest I've come to paying that much for music was when Bad Religion put all their LPs from the 80s to 2011 in a vinyl box set... and it was ltd edition, so I no longer see it in their store. Looks like you got some damn cool booklets and a nice collection, though, plus it's signed, which is awesome!
Dug those two tracks you posted. Guilty Gear X2 was one of my absolute favorite games on PS2, and possibly my favorite fighting game.
I don't think I've ever bought game music soundtracks, but I did buy the soundtracks for a couple movies, MI:2, Spider-Man and Star Wars Episode I, and of those only Episode I is an OST. I don't know what game's music I'd buy, probably a Zelda title's OST or a compilation of rock/metal Mega Man covers if I did. Of course, there's tons of great video game music I'd love to have, I'm just not sure what I'd buy in terms of OSTs.