I won't comment on whether I will buy it or not, since I live in Singapore and stream all the cards anyway.
I believe that the buy rate will be somewhere along 600k-700k buys.
Cain and JDS are not huge PPV draws. Considering that the first fight ended so quickly, I'm sure less people are interested in the fight than before. Many believe that JDS will walk through Cain easily. However, it is the end of the year and I think people are willing to spend some money during this time. The last card of the year has always done decent PPV buy rates. Not to mention that the rest of the card is absolutely stellar.
Anderson Silva ♔
Aldo - Dos Anjos - Mayday - Weidman - Machida - Jones