Dealer markup is temporary and doesn't really factor into what the car is worth. You think someone selling their 1 year old C6 is going to get that extra $10k back? Not a chance as the value erodes from MSRP. Car and Driver's estimate was around $62k (slighter higher than my guesstimate of $60k) though others have said $70k-$75k. While their is use of exotic materials, carbon fiber was used in the Z16 Z06 for a small upcharge. If the Z06 was to be a 1500 unit a year car then, yes, the price would be much higher. If GM raises the price to the $70k+ range they will not be able to maintain the production numbers of the C5 Z06 and we'll likely see the Z06 drop from production if it's not making money.
Do a search through the forum and you'll see complaints about the $65k base price for the new C6 before pricing was released. Don't get caught up in the rumor and speculation and have faith GM will do right with the pricing.
Leon