I think the fastest way to do this is to at first breed lots of greenfin spotanus. I can get them to sell in the range $75 - 90. When you're just starting out, you might have to buy a few batches of common eggs before you get 2 of them. Then breed, breed, and sell like mad, and with all that money, research the environment, and get up to level three. then you will get more of the magic fish to survive in your tank.