'Growing your own', no matter what you're 'growing', to save money has always been a fallacy.
There's a book called, 'The $64 Tomato'.....you should read it.
It's a humorous, realistic account of growing your own.
I spent a lot of money to build my coop/run because I wanted it to function well for me and the birds...safe from predators and easy to maintain for me the keeper with some physical limitations. My goal was/is for the hens to pay for their food with egg sales.
I kept detailed track of the...