WEll... Angelfish are relatively easy to breed... And they school
But you'd need a heck of a tank to handle a whole school of angelfish.
My black skirt tetras used to spawn the day after the weekly water change - if one was to setup the tank properly It is possible one could raise some fry. But Black skirts tend to become territorial as they get old, and thus don't school.
As a side note - raising fry is not a cheap endeavor... Baby brine shrimp eggs and other live foods are not cheap. All the water changes, electricity etc aren't free either. You'll end up spending a LOT more than 2$ per fish to get a school.
When I was getting regular spawns of albino cories, I was raising roughly 100 corys from each spawn. The 3$ I got for each one paid for food, dechlorinator and fraction of the power bill... Luckily I don't have to pay water/sewer in this appt