Be super careful getting used coops. Their poop can carry disesases, as well as their feathers.
Once you get these diseases, you almost cant get rid of them.
You will have to kill the entire flock and try to clean everything.
I never buy chickens, only eggs and let broody chicken incubate. Or you can incubate.
I never buy anything used. I don't want to loose my flock cause someone else sold me contaminated stuff.
You never know. That person may have a disease and he cant get rid of it. So he sells his existing coop, kills his flock, and moves his coop.
You dont want to be the one buying that coop.