You've got a good point. Going to play devil's advocate here, so I want to ask - Do you think that the $ value of BTC rising recently has not had an effect on Cas coins? The market has slowed down recently. Lots would agree.
In late 2013 the price was a lot higher than it is now. The premiums for Casascius coins in BTC were also higher overall. It was a uniquely feverish moment though.