I just got a Meike one from Link Delight for my D700, complete with two batteries and a remote, and a LCD extra function thingie, for £60 recorded delivered from Hong Kong - turned up in less than a week, and seems to work perfectly! Ok its slightly plasticy especially when empty, but less weight is a good thing and in the event I break it or it fails, I've still got some batteries and I could buy another one and still be quids-in compared to the Nikon version...
Alternatively, I could have spent 3 times that on a second-hand Nikon one with no batteries remote etc, for something I'll only use a handful of times a year, hmm, let me think about that for a minute...
p.s.
Don't set the interval timer off by pressing random buttons when the camera is off trying to change the clock without reading the instructions, its quite funny once you realise WTF is going on...