However now I see we're going down the path of "I can buy this consumer PC for cheaper", so I guess it doesn't really matter.
If I need and want a quad-core consumer PC, the Mac Pro is overspec'd (and therefore not competitively priced).
It does make the price delta for Win7 Professional a noise item...which was my point in the beginning. Looking at the price of the software box rather than the total system price is misleading - it hides the part of the OSX tax that is in the hardware.
And yes, I think there should be a $1200 i7 desktop that doesn't exist from Apple.
I'd say $999 for starting price, with $1200 after a few upgrades.