you wont make a profit from selling fish cheap or expensive atleast not a lot . with one species you will flood your market quick then your have all these fish you cant sell. if they were cheap you sell them in bulk and take pennies or you sell expensive fish when you actually find hobbyist that know how to invest in projects and that doesn't always happen if your not doing it for your passion for breeding and raising fish your going to only see it as money and you will see money go into it and not come back out lol.