The other variable to include is the total number of units of all crypto in some years: what I, in the table (Table expanded >) of my post (where you, upvote; thanks!) I called "global supply".

Today there are 1000 crypto, so for when there are 8,000 million people, if there are
example a:

16,000 crypto x 100 million units average (approximately) each
= 1,600,000,000,000 / 8,000 million = 200 coins /per.

1.0 / 200 = 0.005

0.005 x $150.000 = $750, the average price of each crypto.

It's still something much better than the importor fiat ...

But not all crypto will succeed; As well as not all social networks that are released are used daily by many people.
How many will actually be used?
I do not know how consumers will react; Depends a lot on what happens with the fiat without backing, the currencies with backing, and the preference for the precious metals with digital accounts.

Example b:
16 crypto used by all, in some years (Yes ... I always choose numbers that suit me for mathematics... :-)

16 x 100 million units average (approximately) each
= 1,600,000,000 / 8,000 million = 0,2 coins /per.

1.0 / 0.2 = 5

5 x $150,000 = $750,000, the average price of each crypto.

Nothing bad...

Apart, while it is true that the fiat tends to zero, it must be remembered that something is called "fiat": I mean that governments can always create new editions of the currency, before " Boat sinks "(like the rats jumping in time), like Monopoly currency .
The problem (for politicians) is that at some point people will no longer accept a new fiat edition, when the crypto are well known: when more and more friends and family insist on "show me your QR" (that I scan it With the phone to send money), or the method that will used.

Regards.
PS: Sorry for "my" English (w/ Google Translator help)