My take on where the money is:
The money is in your control. That is, by spending as little as you can to accomplish any given task means you maintain more control of your money.
So you still have most of your money now, and you can increase it if you sell anything.
Keeping your cash goes beyond just reducing flock costs. Your flock can reduce expenses in other areas if you put the birds to work. You can reduce or eliminate the need to buy fertilzer, weed and insect control products , lawn dethatching tool and labor and kitchen garbage disposal by the flock turns into no need to buy eggs or chicken to eat.

Cost savers include but are by no means limited to :
Feed - give bugs weeds kitchen scraps and plate leftovers , discarded food from produce markets, grocers too (they will discard broken bags of pet and bird food and butcher scrap) .
Housing: repurpose a disused structure or scavenge free materials to assemble your coop. Applies to nest boxes and roost as well.
Flock: Adopt from rehoming offers on BYC. Hatch a batch cheaper than buying birds.Stock your first aid and flock special need items before you need them and you'll pay less than if you have to make an unplanned emergency run to the store which costs more time, fuel, and you'll likely pay premium price for what you could've got on sale.Take-away: Plan ahead!