No idea, but a few contenders are the Nimbus Supercut of Floyd’s Wish You Were Here, fully signed first Smiths album, fully signed Modern Jazz Quartet Pyramid, Klemperer’s Bach St Matthew Passion Columbia SAX 1st issue, Tureck Bach Goldbergs HMV ALP mono. Those are all worth proper cash.
PS Audiophiles who bought fancy Nimbus, DCC, MoFi, Alto, Classic Records etc vinyl in the past may well be sitting on a lot more than they think. Some of this stuff really is worth a lot now, and thankfully I bought a good amount new!