If you're after a super-cheap Windows 10 PC, the Raspberry Pi 2 could be the answer! I'm extremely surprised to see MS release a version of this little dev board, but it's fantastic news:
https://dev.windows.com/en-us/featured/raspberrypi2support
We’re excited to announce that we are expanding our Windows Developer Program for IoT by delivering a version of Windows 10 that supports Raspberry Pi 2. This release of Windows 10 will be free for the Maker community through the Windows Developer Program for IoT.
Windows 10 is the first step to an era of more personal computing. This vision framed our work on Windows 10, where we are moving Windows to a world that is more mobile, natural and grounded in trust. With the Windows for IoT developer program we're bringing our leading development tools, services and ecosystem to the Raspberry Pi community!
https://dev.windows.com/en-us/featured/raspberrypi2support