Name brand battery grips have always been pretty over priced unless you absolutely need the weather sealing, and if you do, why not just take off the grip and use the normal battery door to seal the camera?
I could never justify spending 200$ or more on a grip. I could use that elsewhere on more important accessories like cards. I've used generic zeikos and opteka grips for years and have worked flawlessly and feel almost as good as the real deal.