I just ordered 10 of the Minimalist Unicorn Controller Boards that I designed. Total cost was around $34 from SeeedStudio, so that's about $3.40 per board. If you want, I can send you one for the cost of the board + shipping. I really only want one for my Unicorn (still haven't used it) so I kinda want to offset that cost a bit. I'll be ordering the components tomorrow so I'll let you know what the electronic bits cost then. Sorry about this post's grammar—it's late but I really wanted to get this out tonight.
Update: This is essentially just the extruder controller with all the unnecessary bits removed. The benefits of this board are that it is (theoretically) cheaper than the EC board and it's smaller than the EC board but it still has the plug-and-play RS485+Power port.
Update 2: Remember, this is just the PCB I'm selling, nothing else—no components. You all knew that, though. Right?