Arduino Uno R3 (ATMEGA328 supported by Grbl firmware)
$21.95
http://www.amazon.com/Arduino-Rev-3-Uno-R3/dp/B006H06TVG/ref=sr_1_1
GrblShield
$69.99
Grbl Firmware
Free
Smooth Idler Wheels (x2)
$5.75 X 2 + shipping
https://www.inventables.com/technologies/smooth-idler-wheel-kit
Dual Bearing V-Wheels (x4)
$4.85 X 4 + shipping
https://www.inventables.com/technologies/dual-bearing-v-wheel-kit
Standard Wheel Carriage Plate
$8.00 + shipping
https://www.inventables.com/technologies/standard-wheel-carriage-plate
Makerslide (1m)
$19.99 + shipping
https://www.inventables.com/technologies/makerslide
Neoprene Belt (1.5m)
$9.95 ($1.99 per foot X 5 feet)
https://www.inventables.com/technologies/open-ended-neoprene-belt
Plastic Pulley with Dual Flange MXL Pitch
$5.50
https://www.inventables.com/technologies/plastic-pulley-with-dual-flange-and-mxl-pitch
Nylon Spacers (10)
$2.00
https://www.inventables.com/technologies/nylon-natural-color-spacer
M5 Button Head Cap Screws (20mm X 3)
M5 Button Head Cap Screws (30mm X 6)
$2.50 for 10 X 2
https://www.inventables.com/technologies/m5-button-head-cap-screw
M5 Socket Head Mach Screw (10mm X 2)
$2.50 for 10
https://www.inventables.com/technologies/m5-socket-head-cap-screw
Nema 17 Stepper Motor
$16.94
https://www.inventables.com/technologies/stepper-motor-nema-17
Eccentric Spacer (5mm hole)
$2.00
https://www.inventables.com/technologies/eccentric-spacer
Precision Shim Washers (10)
$2.00 for 10
https://www.inventables.com/technologies/precision-shim-washer
M5 Flat Washer (2)
$2.50 for 10