Rarest prog album you own?

What's the rarest prog album you own?
For clarification: you must have the physical album, be it vinyl, cassette, or CD (does not count if it was downloaded), and for simplicity's sake, we'll say that it's rare if it's generally difficult to find hard copies of it.

For me, the rarest album I own is an original 2001 copy (not the 2005 reissue) of maudlin of the Well's Leaving Your Body Map.  I'm in the process of tracking down a copy of Bath, which is no easy task either.

Care to share?  I'm guessing that some of the rarest stuff out there are limited quantity recording demos and such.

Tsunami - Anthem of a great wave - 1992, neo prog, rare and damn good, CD, this is one of them, Elsesphere - Blind leading the blind - 2002, prog metal, CD, very good and difficult to find

GentleGiant wrote: the both ZAPOTEC albums

I have albums by bands from my home country which are impossible to buy on the internet or stores in other countries, but that's quite it. I'm not much of a collector, but those CDs will become collectors' items in a decade or two

NecronCommander wrote: For me, the rarest album I own is an original 2001 copy (not the 2005 reissue) of maudlin of the Well's Leaving Your Body Map.  I'm in the process of tracking down a copy of Bath, which is no easy task either.

I've got a copy of Obscured by Clouds where "Free Four" is missing and "Wots... Uh the Deal" appears twice. It's in poor condition though, so I don't think it's worth much.

I've an original vinyl copy of Kaleidoscope's A Tangerine Dream. That was changing hands for £200 a copy in the 1970s but I don't think it's worth quite that much now.

The "rarest" thing I own is a version of Trans-Siberian Ochestra's Night Castle, Beethoven's Last Night, and Lost Christmas Eve signed by the band after a concert. And I don't think that that's all that rare...XD

I have Porcupine Tree's Recordings, which had a limited number of copies and was selling for quite a bit on the web. I heard that it was supposed to be re-issued, but I'm not sure if it has or not.  I'm not really sure how rare it is around these parts however.

Yep.  You can get it new for $297.89 or used for $98.92.

I have autographed original editions of all the early echolyn CDs.

I bought the first 3 CDs by space rockers Darxtar shortly after they all went out-of-print.  I have never seen other copies of these.  "Darker" is listed on www.ecrater.com for almost US$200.  "Daybreak" is now available for free download, sanctioned by the original 2 members.

I've got several pretty rare electronic music CDs:
  Michael Hoenig's Xcept One
  Michael Stearns' Encounter
  Eddie Jobson's Theme of Secrets (autographed)
  several rare Tangerine Dream soundtracks

Some of my CDs that used to be pretty special aren't so special since they were re-released:
  Anglagard original edition CDs
  Khan (Steve Hillage)
  UK's Concert Classics Volume 4 (this was recalled shortly after its original release, but has since been re-issued under a different title)
  Many many Hawkwind CDs

On the vinyl side, I have Planet P Project's Pink World on pink vinyl, and a few rare Pink Floyd/Roger Waters 45s (like the "obscured version" of Not Now John).