If you can't buy or sell without the number; I'd imagine that 'dollars' will be obsolete as ONLY digital (tracking) transactions will take place.
Not so. Without dollar credits in one's account, the bar code (the mark) representing it, or the balance and ID number in one's memory that the bar code represents, would be invalid, either for the buyer or the seller. Otherwise one would have to be an officer speaking/signing for the government (the "beast" which issues the currency), or else authorized by it to make purchases or sell government property.
Elsie, you need to actually read what the passage says, rather than merely accept the meaning that the translators/interpreters gave you. They wouldn't have seen what you and I can see, or what Beloved John saw with heavenly help. Denominated in dollars, that is (which John couldn't see, although he was well aware of the Roman methods of arithmetic using the numerals that add up to 666), but which we can see, knowing how Daniel's eschatology worked out, and that we are still a child of the Roman Empire that ruled all of Europe, the Mid-East, and Northern Africa, still using currency that bears the imprint of its numeral system.
Also, I feel that Roman Catholicism still implicitly consists of the embodiment of the Holy Roman Empire. I would not doubt at all that it would like to be the dominating authority of our nation, and has been seeking it to rebuke the Protestant beginning and underpinning of our Christian American liberty through the years it has flourished more and more.
We'll see how Cardinal Burke makes out with his rebuke of the openness of his (South) American-born Pontiff.