You're feeding them the wrong stuff. They can live off of cracked corn and whatever stale bread and vegetables you toss them, as well as bugs in their general vicinity. As for the initial buy, they can turn over a new generation in about 3 weeks. You can also eat the old chickens. You're looking at it wrong.
Because I'm not looking at it the way you look at it? Been at it for ten years and am perfectly happy with how it's been going.