very few people buy Windows off the shelf, and MS knows that. Besides, whle it is more expensive than Mac OS, there is far longer between versions, so it evens out.
What I don't like are companies like Dell who dont even give their customers a Windows install disc, but instead a restore disc which is just a disc image. This means you can never have a clean install, because dell slipstreams all sorts of crap with their installs. It also causes issues when trying to repair an installation because you cannot run the properwindows installer.
i hope this trend changes with Vista