"The new BeagleBone Black is selling for 45 dollars and:

is open-source hardware that combines the capabilities of a microcontroller and a Raspberry Pi into a single board. It features a single-core Sitara AM335x ARM Cortex-A8 processor clocked at…"

"Would this board be of any interest as a starting point? Here's the blurb:

Raspy Juice is an experimental expansion board to supply a Raspberry Pi (RPi) host computer with a regulated +5V from a wide-range voltage source. The board also contains a…"

"It is mostly a publiciy platform for Newatk/Farnell/Element14 which makes practically no money with it (compared to its distribution business).

This is totally untrue. The rationale for the Raspberry Pi Foundation (a charity) can be found here…"