So this is a thing sponsored by Xbox -- pretty cool.
Starting Friday, you'll be able to log on to Halo Waypoint and equip your Spartan with the armors, helmets, and visors you've unlocked via REQ packs, then send the final configuration off to be printed. A small (4-4.5" tall) figure will run $29.99, medium (5-5.5") figures will be $49.99, and large (6-7") will be $89.99. That's roughly $7.50 per inch, $10 per inch, and $12.86 per inch of Spartan, respectively. Shipping will be free until December 6.