Now the question: what does it get you? Basically nothing. The resistance of bearing seals at the bottom bracket means next-to-zero in terms of resistance to your pedaling. There have been other threads on this. Save your money. Unless the Dura-Ace bearings are crapping out on you due to your hammering in a way that a pro sprinter could only dream of
Here's a recent and informative thread on the matter. And
another, similar opinions but somewhat less informative.