Most people have a problem with trying to fully understand large numbers like a billion or a trillion. Somewhere between learning addition and subtraction and learning that one infinity can be bigger than another infinity a teacher will likely use the thought experiment of stacking dollar bills as a way of demonstrating large numbers.

Watching this video about the increasing cost of the current war between Russia and Ukraine made me think about how in the modern economy using amounts of millions and billions is commonplace.

A U.S. one dollar bill is 0.010922 cm thick. multiplying that by a thousand, million, billion, trillion, ect. gives the height of a stack of dollar bills. Since the U.S. doesn't traditionally use metric when measuring most websites list the thickness of a $1 USD as 0.0043 inches so roughly 233 $1 USD for an inch high stack. According to ehd.org a stack of one billion $1 USD bills would measure 67.9 miles high.

Meme Source

I am not sure what "the cost of war" would mean in a post-scarcity economy. There wouldn't be as much of a need to fight over resources but land is not fungible and neither are the human lives of soldiers. Like the above video points out there are costs of war beyond financial.