I went back to my chicken math post from 10/17 and checked my spreadsheet. I have some updated numbers and projection on how much chicken feed I'm using. So here are my updated inputs/outputs numbers:
Chicken chow: $20/bag, lasts 6 weeks. (Actually $17/bag plus tax.)
Eggs produced: 1.6 average per day, or 11.2 per week (includes the first week, but only counts edible product)
Eggs produced after the first week: 1.7 average per day, or 12 per week (edible eggs only)
Cost of a dozen "free range" eggs at the farmer's market: around $4. (I can find them for $3.50 sometimes.)
To break even on just the feed costs (not the cost of the actual chickens, coop, etc.), I should produce approximately 5 dozen eggs in six weeks. Right now, I'm on track for a smidge under that. And these are my winter numbers. As the days turn around and get longer next spring, the chickens will start laying more. I'm very encouraged.