What I know about ECCC 2012 so far:
EBAS: $100, stand in line 1 hour pencil sketches
Tim Sale: Fast Pass (likely 30-45 mins per piece) - $250, but I'm told he will occasionally take on a 2 character piece for $400-$500
Eric Canete: $100-$300 (not sure on the details, and Eric is no longer doing licensed character....refer to the Gary Freidrich thread)
Tony Moore: $200, takes names and requests then picks which ones he wants to do that day, unless you won one of the guaranteed ebay auctions.....which I did
Clay Mann: $400 for a single figure color piece (I'm told you can get background for a little extra)
Ben Templesmith : $350 - 11x17 max 2 characters