At the March 2016 meeting, a few people where interested in where the ball screw was purchased from:
Note: RH NEMA17 motor and 3D printed mount are not included. Also the 10mm - 6.35mm coupler does not natively accept a NEMA17 stepping motor's 5mm shaft.
See AliExpress: http://www.aliexpress.com/snapshot/7192568752.html?orderId=71722736374152
SFU1605 L=300mm ball screw + 1PCS ballscrew ball nut 2 X 6.35*10 Coupler + 1 X BK12/ BF12 Support CNC. At the time, I paid AU$92 for the set.
It's way over spec'ed for what I wanted it for, but you use what you have at hand.