Curious, enegmatic even, but I'd be more interested in the book than the record which sounds like some sort of 'outsider music' from the sound clip. I could find a lot better use for the asking price as well. If it's that big a deal it should be reissued cheaply. The whole thing looks like a Stephen Poliakoff story!
I guess this is rare, but a major label even in Mexico must have pressed at least a few hundred. You could get an one off unreleased Beatles acetate for that kind of money. I'd like to hear it, but it won't keep me awake.