There are pleanty of interesting cats that are rare in the trade but are common in their native enviroment, fish like Meredontotus tigrinus, Goslinia platynema, Asterophysus batrachus, Psuedopimelodus fowleri and Hemibagrus wyckii to name a few that are all high priced fish in the trade but considered food in their native countries.
S.granulousus is the only cat i can think of that is both sought after in the aquatics trade and rare in its native enviroment.