The CullMill is an in-progress project to create a 3D-printable PCB mill for less than 60 USD (excl. printed parts), with the help of cheap electronics and few materials, as well as a 3D printed body, done in the spirit of RepRap.
At the moment, the hardware design isn't finished, and there is no code, so there isn't much here yet except for the first (version 0.1) mainboard. All it's electronics (incl. steppers) clock in at about 30 USD, leaving half the money for hardware.