Makes no sense for any of us to do this because the price would fall down again after we stopped buying. For someone with deep pockets and big plans, this may just be the way to go, however.
Ahh the speculation game. What would happen if someone seriously tried to do this?
I am guessing that it would cause the price to shoot at least past $200 per coin. Keep in mind he wouldn't be doing this in a vacuum, and plenty would jump on his bandwagon. It would also cause bitcoin to jump back into the news, and attract new investors.
He would probably be best served by doing it all in one shot in mass (this way he gets ahead of the hype). What would be crazy is that if one $100M person jumps in, it makes another start to think it isn't that bad of an idea. And once you have two people...