As a side question, this part worries me more, say BTC reaches 1 Mil (lets just imagine) and you do have 1 BTC or more, which exchange will actually cash out that much money for you, is it even factual !?...
As far as I know, when the price of bitcoin reaches the highest price (as expensive as anything is it, or becomes 1mil as you say), I'm sure it is the price agreed upon by the bitcoin holder, or people are willing to spend that kind of money on one bitcoin.