Hang on, as it is this game looks a little broken. If multiple people pick 100 (which DID happen and might very well happen again), and at least one person doesn't, the best option is to pick 100. Admittedly this isn't THAT big a problem at the moment, because the four leaders might back down, and leave one person picking 100, but if this game were to be repeated you would essentially see nothing but 100s in the first round, and anyone who didn't pick it would be losing it.
This game is a much less of a multiplayer game than it is a puzzle with a solution (based on how many people pick that solution).
With all that said I'm still in a solid 5th place, so prepare to die, everyone else.