OP - When I purchased my laptop I asked dell if they would do this and take money off the price. They said no. OEMS like DELL pay something insanely low for software I believe and then charge us full price for a profit.
Thread on it is
here.
Also this is something customers can purchase.. I remember hearing that system builders especially those as large as dell would get windows for < $50.
I have actually heard it being < $10 but am not sure of that source since I worked for the company and well not everything they did was a on the up and up.