Michael Silver, a Gartner analyst, said that just because Linux is free does not mean it is cheap.
Linux is be less expensive than Windows because StarOffice/OpenOffice.org can be used instead of Microsoft Office
Linux is free
There are no forced upgrades. ("We expect there to be as little support for older versions of Linux as for older Windows," he said.)
Linux requires significantly less labor to manage
Linux has a lower TCO than Windows because of the available management tools
Applications are inexpensive or free
Skills are transferable
The hardware can be kept longer if Linux is used, or older hardware can be used;
Linux should be deployed as soon as a Microsoft Enterprise Agreement expires, and
Linux on the desktop is an all-or-nothing equation.