It is a collectible. There is no good way to value them.
Bear in mind that once you buy them, the bitcoins are transferred to you and the value decreases.
Permit me. I want to get an understanding does it mean when I get for example a 1btc coin, will the value now decrease to say 0.09btc? Also, I want to ask on the coin, will there be a way to redeem it and covert to the coins we all transfer into our individual wallets? An answer will be appreciated because I have seen some auction done for physical bitcoins which I have require more information.