And just what is a Mac besides "UNIX for Dummies?" OS X is nothing more than FreeBSD (A UNIX derivative for the non geekazoids) with a user interface that anyone can use.
I find it remarkable that the upgrade to the latest version of OS X was priced at a mere $30. How much is Windows 7 Upgrade again?
I did extensive ROI comparisons at the last place I worked between a low end iMac and the average Dell/HP type workstation. You could buy 3 of the PCs for what the iMac cost you, but software licensing, upgrades, and manpower to maintain the PCs drove the total cost of the PCs to well over twice what the iMacs cost over 5 years.