Based on what I've seen from Barrett-Jackson, Mecum, etc. $400K is a bargain for a car like this. However, value for cars at this level is simply based on how much someone is willing to pay for it. The car could've gone for $800K+ but "that" person was not in the building when this auction took place. It's an amazing car though considering the history and association with Fred Gibb.
2011 Summit White Camaro 1SS/RS
-6.2 LS3, TR6060, 3.45, G80
2004 Black Silverado 1500 2WD Regular Cab, Short Bed
-5.3 LM7, 4L60E, 3.42, G80