To me, all marine fish are unique and rare in their own right, and their value goes well beyond the dollar figure assigned to those sold in the marine aquarium hobby. As we see more and more species, capable of being bred in captivity, I am not sure what the outcome will be, say 10 years down the road. A best case scenario, I think, is that hobbyists have sources for both healthy and substantially captured marine fish, (since captive breeding will likely never be able to re-create wild diversity) and captive raised species, as they are known to be hardier and readily adapted to aquarium life.
That said, the most important issue that has arisen, that will ultimately effect fish costs, is environmental. It is vital that collectors worldwide are compensated for their efforts, and trained properly in capturing fish and maintaining their health up until the time of export. Paying collectors in remote locales minuscule amounts for marine fish, regardless of rarity, encourages them to pick up side work for the food industry or worse, the limestone industry. These two options can be very devastating to the environment, whereas sustainable collection is not.
If we could a higher percentage of captured marine fish to live, and offer a larger diversity of captive bred species - a bit of equilibrium could be established. There are many factors, one being fish outlets that don't properly educate new aquarists about species care or environmental conditions.
I believe, in order to help guarantee that resources both for captive breeding and wild collection hold out for generations to come, it is inevitable that prices for fish from either source, will go up. Sure, more rare species may be readily available because they can be captive bred, but their rarity should be determined more by the populations in the wild, not by our ability to breed them in the aquarium.
