At work, we needed a PC for a Linux-based Webkiosk the other day. The computer proposed by the colleague who actually orders stuff comes with a Windows license. I said we don't need that. A fruitless, lame effort was made to locate a substitute w/o a Windows license. I renewed my protest, but the feeling that the problem is me was already floating in the air. I gave up. We purchased a Windows license to run Linux. For the umpteenth time.
It's like a Microsoft tax on PCs.
Those OEM licenses do seem quite cheap. I think it was Dell who gave an option for a while. To remove the Windows license and have Ubuntu instead only saved $10.
It was low enough where I think most buyers questioned if it would be worth it to have the license just incase.