This is really a collector's item.  It's not only signed by members of this supergroup,  it's also signed by Mick Jagger, Dave Stewart of the Eurythmics, and A.R. Rahman.  Not cheap, but a real addition to any fan's wall.  As they say, "bid 'em high and sleep in the streets."  (Of course, then you wouldn't have a wall to hang it on!!)