Is it possible that he might have spent almost $1 in materials and labor and allocated capital expenses on equipment ... to create each of these counterfeits.

Attempting this today would probably surely cost that much in today's dollars?

EDIT: on a second thought ..this almost feels like "proof of work" for currency :)

The U.S. government spends approximately 4.1 cents [1] to produce each $1 bill. It would probably be more expensive to counterfeit it because of the volume, but I doubt it would be more than $1.

[1] https://www.federalreserve.gov/faqs/currency_12771.htm