Good luck!
I would try ebay. These things are not cheap and I highly doubt you'll find one below retail. Especially since they are currently out of stock on the jawbone site.
you can get one here:
Introducing the brand new Jawbone Bluetooth headset
NOT AN AD...I HAVE NOTHING TO DO WITH THEM AND DO NOT EVEN OWN ONE.
Or there is this one on ebay:
eBay: PRE-HISTORIC FOSSIL ROCK JAWBONE TEETH MOLARS (item 170093010784 end time Mar-21-07 15:00:00 PDT)