Just my two cents... worth exactly that:
It's really nice of Underworld to even make this available outside and beyond of the limited duration exhibit. If i were to attend a gallery show, i can definitely forsee paying a similar amount for the art catalog and a media piece, be it DVD, CD, print, otherwise.
That said, how many have heard the CD in its entirety? I'm sure it's amazing, and much as i like to have/collect as much UW as possible, i do think it was a bit pricey for international delivery, but then, it was very limited edition and certainly more of an art piece than a release for mass sale. So, the fact that it's now sold out makes my decision easier to live with, I don't need to have everything i want.
still..would be cool to hear this at some point!