One can always shops around and find a lower price than the manufacturer's recommended retail price, but comparing RRP prices in Australia, I find that the Nikon D3 is A$7499 and the D3X A$13,999.

Since we often compare noise and dynamic range at the pixel level, why not compare value at the pixel level? If we do that, we get 0.065 cents per pixel for the D3, and only 0.058 cents per pixel for the D3X. That seems a fair 'quantity discount' to me, for the D3X. What are you guys complaining about?