I'm fairly sure that Audio Fidelity only pressed 2,000 copies of Spectrum. Add in the fact that it was a "previously unissued" quad mix when AF got approval for release, and it was bound to be somewhat more in demand. It always sells well when it get a reissue on whatever new format it arrives on.Passing on Billy Cobham's Spectrum (if confirmed) is rather strange as it's a classic of jazz fusion, and the quad mix from the previous MC SACD release is great, but it's been OOP and the cheapest on Discogs is US$174.