there's a new thread on reefcentral discussing the availability of Chaetodon wiebeli.
i really like this butterflyfish and it's very common in thailand, japan and taiwan. but they are just not collected for the trade regularly enough. infact, most of these end up as by catch and sold in the local countryeither as food fish or as cheap by catch fish.
they seldom get exported out and are just not targeted for collection.
they are very common as can be seen in this swarm in japan. dr. tanaka who lives in miyazaki, occasionally see juveniles swimming near the surface of the harbor. easy to catch!