You make no mention of feed cost. Do you just depend upon free range "pecking" in the grass, or kitchen scraps... or what? 13 chickens is a lot of daily feed!

I view the feed cost as being the yin to the egg production's yang. I'm not keeping a spreadsheet, but I do believe they produce more value in eggs than they ingest in feed.

In the warmer months, they also supplement their food from the yard when they eat a lot of grasses and fruits