Worked in fish retail and 100% it is bread and butter species that are of interest. Namely because if they can guarantee supply, provide quality fish, and undercut importers it makes sense to them. Sure if you can breed zebra plecs you might sell some, but how many people are gonna drop four hundy on a pleco? Most people just want the normal affordable ones. Either establish a relationship with a retailer or send them to multiple stores...however, this is unlikely. Hobbyists who supply stores tend to do so on a personal basis with the owner from my experience.