Suggestion: Buying value x Current value

Hi,

I think that would be interesting to have a field for the current (market, catalog,...) value of a coin.

Most of my coins were bought decades ago (and several monetary reforms) or gifts from friend or relatives, so its today Buying value is zero, not not its current value.

And for those that have a buying value, a new field would make easier to keep track of coin's value change over time.

thanks.