Why is the Nikon MB-D80 (MBD80) Battery Grips so cheap on ebay?

I want to get a Nikon MB-D80 (MBD80) Battery Grips for my d90 so i looked on ebay and most of them are under under $100 is there something different about them or are they just really cheap

Most of the ones you find on Ebay aren't real Nikon grips. I've encountered the same thing with Nikon batteries, chargers, as well as grips for my cameras.

Look carefully, and the product in question won't be an OEM Nikon product, but is a replica. Now, if you want an inexpensive grip, most will work well. I've used a few in my time.

But, don't expect the fit & finish, same controls, or same quality of material that you'd expect from a Nikon product.

Yes, I agree. There are a lot of inexpensive aftermarket grips for the D90.

As well, it has been discovered that for the D7000, there are some counterfeit grips. Not sure if the same thing exists for the MD-B80 or not.

http://www.google.com/...oQ&cad=rja

On the other hand, the MD-B80 is only compatible with the D80 and D90 as the D7000 uses a different one. Since the D90 is at it's end-of-life cycle, perhaps they are on discount to move them out? I dunno.

I have a genuine MB-B80 for my D90, and it usually sits in the closet. I only use it for counterbalance when I use my heavy Nikon 80-200mm f/2.8.It makes the rig more balanced. Otherwise, it just adds weight and bulk to the camera, and I can just as easily carry the spare battery in my camera bag.

If it's too good to be true usually it's not. There are original Nikon products and there are compatibles. Look again and check very carefully. There are even existing battery grips that only hold the battery without the extra shutter button for portrait orientation.