Does the face value mean anything? Legally yes, practically no. A $2 Niue coin containing an ounce of silver is legal tender for two dollars in Niue, and nobody would ever spend it. The denomination exists to establish legal tender status, which is what separates a coin from a medal.

Denomination is useful mainly as a fingerprint. It ties a piece to its issuing country and often to a specific series, which makes it a precise way to narrow a search when you already know what you are looking for.

If you are weighing what a piece is actually worth, metal weight, mintage and grade are the fields that matter.