Nice job on the coins, they are cool. However the trust factor is way to high. I went down this road myself when I created the gold plated CoinBit http://CoinedBits.com.

The original consumer has to trust that Casascius isn't selling them a zero value coin. The circle of trust then gets wider if the original consumer tries to trade the coin. The second person receiving the coin now has no way of verifying the coin originated from Casascius.

Counterfeiting this coin would not be difficult, and would be extremely lucrative if the Casascius coin gained adoption.

This is why I ended up keeping the CoinBit as a novelty or souvenir coin.