Breeding fish is no get rich quick scheme.
Some independent (true) aquatic shops run by proper aquarists may reward your efforts but be aware that they too will be wanting to make a profit so the best you can come away with is a credit note. The more likelihood scenario is for you to exchange for food stuffs and the likes. This will all be dependant on what species you are offering, what condition they are in, your reputation with your LFS, and if the LFS owner can shift your stock.
It is also the responsibility of the breeder not to breed so many fish as they cannot get rid of their surplus, this is bad practice, so it's up to you to find your outlets be it local auctions or dealers, build a reputation and breed your fish responsibly. The best way to earn a reputation is to get involved in your local aquarist club and find your niche and stick to your chosen genre/species, learn everything there is to know about them, listen to dedicated breeders note their methods and try to improve upon them. This in itself requires years of input on behalf of the novice breeder.
As in any walk of life there will be spoofers out there the art is telling which folks are true aquarists (folks that you should be listening to) and others which are just playing at it. Controversial words I know...but true.
Sorry if that comes across as patronising.
Best of luck
Regards
C