I will give you some of my limited insight. My friend breeds balls mainly for himself and he is of the mindset of many others. Holdbacks and sell the rest. He has in excess of 30 breeder quality and as a result a while back started breeding his rats. He now has an excess of rats that cost him 30-60 dollars a month to feed.He sells what he cans. He has slowed to the minimum amount of rats he needs but still has excess. Everything cost money, and as such needs to be evaluated. I am looking at the following just to be able to have this as MY HOBBY
Cost
Space
Feeding
Cleaning
Time - Time - Time
Food Source
Vet bills
and the list keeps on going...