Well you don't have to sell them all at once. Just slowly sell them in small chunks. The interesting point is that it seems Satoshi hasn't sold _any_ of them.

Allowing him to buy more of them for a very cheap price.

Err... Suppose that works. Take it to the logical conclusion: Satoshi drives out every buyer and buys up all outstanding bitcoins. Now what? Bitcoin has become worthless. What does he do with 10m worthless bitcoins to cash out? This is the classic question in attempts to corner a market: how do you bury the body?

When you hold as many bitcoins as does Satoshi, you will profit far more from not selling and trying to help out the entire Bitcoin economy and make it grow.

I'm thinking it is more of a DeBeers situation. Keep tight control over the supply.

BitCoin already has a hard limit hard-coded into the design. You don't need to hoard 5→10% to achieve scarcity.

That requires convincing people they want BTC. And BTC users are male, whereas diamond consumers are women, so differing marketing strategies are needed...