The Great Flood of Noah's day was only about 4300 to 4400 years ago. Since that flood wiped everyone except Noah's family from off the earth, that means that the currency system isn't more than that old.
In addition, the currency almost assuredly wasn't used by Noah. What would he use it for? Any barter he did, would have been between him and his children and grand children, etc. Who needs money for that?
Probably the oldest money system that we could connect to is way less than 4000 years old.
You do realize pyramids are older then that. As well as some trees. Trees for god sake. Not to mention a lot of other things that would not be possible if human population was reduced to one family. In addition, the currency almost assuredly wasn't used by Noah. What would he use it for? Any barter he did, would have been between him and his children and grand children, etc. Who needs money for that?
Probably the oldest money system that we could connect to is way less than 4000 years old.