I see a table to look up a number. I don't see a calculation though.

If I know the actual weight of silver in a coin, I can divide that into the value of silver and come up with the precious metal value of the coin (intrinsic value in dollars). That's what I used in buying the coin. Why shouldn't I use the same formula when selling the coin? I'm only interested in how much the coin appreciates in value due to the appreciation in value of silver metal. I don't really care about the small amount of copper in the coin that may appreciate or depreciate in value separately from the silver value.

If the value of the precious metal goes to infinity, doesn't the coin have infinite value? If the value of the precious metal goes to zero, doesn't the coin have zero value? As long as the mass of the precious metal stays fixed at the amount put into it when manufactured, either method should provide a useful comparison.

It looks to me like I'm going to have to modify my offering value. I would like to know why, though.