While there are a lot of valuable old coins out there, perhaps none have enjoyed such an enduringly mysterious origin story as this half-dime.

Here's a rundown of U.S. Mint production costs from the government's latest fiscal year. Each penny costs nearly 4 cents — or $0.0369, to be exact — for the U.S. Mint to make and distribute.

The United States Treasury has put in its final order of pennies, and production is expected to end early next year. Here's ...