+1 on how good the second discs from DSOTM & WYWH Immersion Editions are. I haven't looked at the setlist for The Brighton '72 show, but from what I remember, the bit from Wembley '74 gig is about half the show, maybe a little more.
Perhaps The Floyd will take a cue from The Grateful Dead (or the Stones), and open up the vaults. It doesn't take someone with an economics degree (er, well) to figure out there is money to be made.