The problem is that flows like GDP count the "same dollar" multiple times. When the dollar moves from one place to another, it's counted. (To preempt the pedant

The problem is that flows like GDP count the "same dollar" multiple times. When the dollar moves from one place to another, it's counted. (To preempt the pedants: Yes, there are exceptions as to exactly where these counters are. Not every movement is counted.) That's drastically different from having to have a large pile of "different dollars" to make a large purchase like this.