I've never heard of Rev 13 prophesying a monetary system... but here's a breakdown of those verses as I've studied them:
A tiny bit of backstory needed though, we'll start with verse 11.
11 - 13: Then I saw another wild beast ascending out of the earth, and it had two horns like a lamb, but it began speaking like a dragon. It exercises all the authority of the first wild beast in its sight. And it makes the earth and its inhabitants worship the first wild beast, whose mortal wound was healed. And it performs great signs, even making fire come down out of heaven to the earth in the sight of mankind.
So, beast number two. It has two horns, representing a dual partnership between world powers. It comes out of the earth, not the sea, meaning it spawned from what was already in existence. It's the final world power mentioned in the Bible, the British-American dual power that rules the planet. It's two lamb horns makes it look mild, unoffensive, enlightened. But it's dragon speech means it uses pressure, threats, full on warfare against anyone who disagrees with their views of democracy and "freedom". It makes people worship the wars of the past, WW1, WW2, rememberance day, etc. etc, further strengthening the national patriotism that divides the world. Thus, worship is turned to the original fractured 7 headed wild beast. The great signs it performs, obvoiusly, are the massive technological advances we've seen in the last century, John making reference to Elijah's story (1 kings 18:21-40) where he made fire come down from heaven as proof of his authority.
14: It misleads those who dwell on the earth, because of the signs that it was permitted to perform in the sight of the wild beast, while it tells those who dwell on the earth to make an image to the wild beast that had the sword-stroke and yet revived.
The purpose of the Image (like any other image of a god figure) is to promote worship of the Wild Beast and perpetuate its existence (as you know, a god without worshipers is dead) In the timing of events, the Image is made after the Beast recieved its deathblow and was healed, so after WW1.
15: And it was permitted to give breath to the image of the wild beast, so that the image of the wild beast should both speak and cause to be killed all those who refuse to worship the image of the wild beast.
The second Wild Beast (aka British-American power, see above) gives life to the Image, so that it's alive and can function. This is the beginning of a new and different power, created by the Brits and Americans and initially known as the League of Nations. It "speaks", making claims that it is the only one who can bring peace and security to the world. But in reality, all it can really do is speak. It "causes to be killed" nations who disagree with it's ideologies, expelling them, enforcing sanctions and whatnot.
16 - 18: It puts under compulsion all people—the small and the great, the rich and the poor, the free and the slaves—that these should be marked on their right hand or on their forehead, and that nobody can buy or sell except a person having the mark, the name of the wild beast or the number of its name. This is where it calls for wisdom: Let the one who has insight calculate the number of the wild beast, for it is a man’s number, and its number is 666.
Six is symbolic in the Bible for imperfection, one short of a perfect 7. Also, words or phrases are repeated three times for great emphasis in other parts of the Bible. Therefore the name/number 666 represents an extreme imperfection, massive failure. And the name given to the Wild Beast (the first one) is 666. Calling it a man's number, John confirms this is no spirtitual or demonic entity. The beast is a symbol of earthly human government.
In Deut 7, God tells his people to put his words on their heart and soul, and put them on their hand and their forehead. In Rev 14, the 144000 anointed ones are said to have the name of the Father and of Jesus written on their foreheads.
So in a similar way, anyone buying or selling or being involved in day to day society in this failure world would have to accept that mark on their hand and forehead in order to be accepted into the world. Refusal of this mark leads to being oppressed and attacked. If you live your life in a Christian way, you will never become rich. You will never be a decorated hero. You might be jailed. Religions will attack you and kill you (lookin at you, ISIS). Basically, doing things God's way in Satan's world leads to a tough life.
TL;DR, the marks on the hands and foreheads are completely symbolic, as is the large majority of the book of Revelation. Compare Deuteronomy 11:18 for the symbolism, also Revelation 14:1.