Originally Posted by kimcmich
Home fly culture is certainly the most economical generally speaking and many people do it dependably and cheaply.
I, however, am happy to pay for the convenience of someone else doing the culturing: I get 4 cultures (2 new, 2 producing) from Josh's Frogs delivered every 5-6 weeks (enough to feed my 15+ thumbnails for that duration). It costs ~$45 per order so less than $10 per week. I don't have to worry about mites or genetic decline and the only cleaning I do is to spray the plastic bin I keep the fruit flies in with rubbing alcohol between one batch and the next.
If culturing is your main pain point and $10 a week doesn't break the budget you might want to give retail flies a shot.
The reptile, etc. culture where I live is booming, yet there is never a producing fly culture to be had. I'm managing, I'm just pointing out how this part of the hobby was glossed over and simplified when I did my research. I spend $120/month for live food for my fish plus frozen food, so the expense is not the gripe. I've ordered producing cultures from Josh's, paid the $39 shipping fee and got cultures with barely enough flies to even feed once and start another culture. My cultures are going well now.