It may be that Dave's biggest mistake was to place too much faith in what Bilstein was telling him about these breakages - re: "we can't make them stronger... the shocks are up to spec", etc - and instead go with what his gut probably told him about these parts a while ago.
Here is the post where Dave mentions the cost of swapping everyone to Konis. It's only $1.3 million.
http://www.ffcobra.com/forums/showthread.php?t=193060