Hmmm, at a 1/4# feed per day, one 50# bag is 200 days of food. If a chicken lays 4 days out of 5 (almost 300 eggs per year, not unproductive), that's 160 eggs per bag of food, or about 13 dozen. If you don't have to buy cartons, you need $3/dozen to cover feed costs. If you need cartons, that $4/doz to break even on feed. Except you need to raise them up to laying age, that's a 40# bag of grower, and pay for your bird stock as well, if you aren't hatching your own. Assuming you get a year of lay +, that's 40# grower plus 100# adult = $100, divided by 25 dozen eggs (breakage, winter, replacements) = $5/dozen with cartons.
and I've not calculated licensing...
Yeah, glad I'm not in your neck of the woods. I can get $2.50/doz, $5/30, buyer provides the container (helps immensely). and of course I breed my own replacements. But I also can't claim large/extra large eggs.