The first glow-in-the-dark "Prehistoric Creatures" coin definitely sells for more than its issue price ($29.95) on the secondary market - most recent "sold"
ebay auctions are in the range of $100 to $115 (they sold for more just after the coin's release).
The second coin of the series is not doing nearly as well. Recent selling prices have been in the $35 to $40 range. The third issue is still available directly from the
RCM for $29.95.
I think it's possible that the price on the first coin will come down a bit more before stabilizing. I don't see the two more recent coins taking big jumps in price, however.
The novelty of the coins has worn off quite a bit and since it was their "novelty" that was driving the market for them, I don't believe that the short-term outlook is very bright.