Um.... Although cool, it's still a pig. Around 3870 pounds (almost 300 pounds more than it's 1968 era cousin). So when factoring in horsepower to weight you don't need a Z06 to compete with it, you can do that with a stock 2008 Vette. A Z06 will destroy it and with the prices dealers will get for the GT500KR you would probably have money left over if your bought the Z06. See the calculations below:
GT500KR: 540/ 3870 = 7.16 (p/h)
Stock C6 2008 Corvette: 436 / 3215 = 7.37 (p/h)
2008 Z06 Corvette: 500 / 3147 = 6.2 (p/h)
With a simple gear change in the stock 2008 C6 you could run the same numbers as the GT500KR and save around $15,000 off sticker, but more like $25-30,000 after the dealers get a hold of it. Just my .02
--Mike