If you tend to react positively to gamification (basically you're motivated by the easy to track progression, achievements etc. like in the screen above) then it might be worth the price of admission. For me, it's just a flashy overpriced toy, but at the same time, I can't hate on a device that has the potential to improve users health. So again, it comes down to a person, if you get motivated by easy to track progression than I'd get one.

Waiting for @herpes4life to come in and post a picture of a 'fit bit' he's found somewhere