I don't see any peeled Cas coin being sold lately but as far as I remember. People tends to buy brass coin for 200 to 250$ and silver is way higher than that, Not sure about the exact price but the physical coin value itself does not change in fiat.
Most the transaction of peeled cas coin is via PM because there is no define value for it so usually buyer make offer in private.
Some peeled cas coin thread:
https://bitcointalksearch.org/topic/is-there-any-interest-in-peeled-casascius-anymore-5300619
https://bitcointalksearch.org/topic/two-05-btc-casascius-coins-for-sale-edit-possibly-been-peeled-5305098