Here in PA, we got an 'assemble yourself' precut 10x10 shed from Home Depot for $750 (includes sales tax). We will still need foundation blocks and florring, some 2x4's. We have 6x6's for cross foundation, and left over shingling for roof. Our total cost is going to be under $1,000 for the initial building.
We are adding a lean-to to one side to store our garden supplies. We have an existing 10x10 chainlink dog kennel to use for the 'secured yard, though I've decided to add a handbuilt section and make that yard 10x20.
They will have large free ranging yards attached to that, enclosed with electrified poultry fencing to deter predators. The little buggers will have a lay quite a few eggs before they make a dent in the initial investment!