Of course price would increase if everyone uses it, but, technically, high price is not necessary for everyone to use Bitcoin. For rough estimate, there are 12

Of course price would increase if everyone uses it, but, technically, high price is not necessary for everyone to use Bitcoin. For rough estimate, there are 12 billion of $20 notes in use, which is $240B, which is 6M Bitcoins. $20 bill comprises the bulk of money circulation. There are more $100 bills, but they are mostly used for savings.