I'd love to say it cost substantially less than prefab coops- but truth be told with lumber, fasteners, roofing, hinges, galvanized welded wire, pea gravel, paint and other add ons- about $900 (200 over my original budget). You could do way better with salvaged materials- but I had a week off and hadn't scouted out available recycled options. The upside is it withstood a trip of st Bernard's who hopped the fence and tried to infiltrate the run. So it is secure.