Well from what I'm gathering from you is, if your looking to make money. Go big or go home. I know its blunt but its real life
If you want to fool around with pocket change than do it on the side...but if your trying to make a steady income get ready to have some money to get you buy in hard times.
Focus on fast growers. I have a list I've been gathering of fast growers so I can remember them all as my head has enough stuff in it
Also try to focus on some specialty corals, and other color morphs as they'll bring in more cash.
You sound kinda scared to make the leap, its a big decision leaving another job for something you don't know if it'll pan out.