I have a guaranteed taker for 50 1" fish every month so I'm good. Culls can be used as live food. So it's up to $600 a year!
I'm planning on good planting, just light sponge or similar filters. Plants or half cups should help the fish nestI think you are better off unheated with paradise fish as mentioned. I found them pretty easy to breed and almost any pair seemed to spawn, given a well planted tank with lots of hiding spots. They are not the most marketable fish, at least not in my region.