The OEM BG-E11 Battery Grip for the Canon EOS 5D Mark III (seen here) runs for over $300 dollars, still out of reach for something I don't think I would use very much at this time. I have had aftermarket battery grips for my 5D Mark II, 7D, T2i, and 60D to add more grip space on the camera body, and to also add that handy extra button when shooting photos in portrait mode.
Now that the Aftermarket BG-E11 Battery Grips for the Canon 5D Mark III have come down to just a little over $50 bucks, I felt it was time to try it out. From the images, it looks pretty spot on with the real deal as far as button layouts and includes the little joystick. I won't have an OEM version to compare it to side by side, but i'll take some pics as soon as it comes in. Check them out via eBay (Click Here).
Aftermarket BG-E11 Battery Grip Canon 5D Mark III -via eBay