My 10'x6' raised coop was maybe $200.
I built it inside my barn in a corner, so half of the walls and some structural posts were already there.
Traded some (future) eggs to my neighbor for his dog run and swing set (now a chicken run and 4x4 cedar structural posts).
I recycled all the plywood from shelves in the barn (walls and floor), floor joists are 2x4s from pallets, reused most of the nails, door motor was from an old aftermarket car window motor.
Railroad ties around the run under the coop from my neighbor, door (and hinges) was in my basement when I bought the place. Windows from an abandoned camper trailer that came with the property. Roosts are black locust limbs from my woods.
I had to buy a tarp for the roof, 2x3 rafters, 2x4 roof beam, 1x3 wood for a poop drawer frame, hardware cloth, staples, screws, hinges to fold up a section of the floor for access inside, pvc and hdpe parts for feeder, pvc, nipples, hose, hose bib for waterer, dpdt switch for door motor, and timer for the switch.