I ended up building my own coop, but if someone would have had a smaller used chicken coop for sale for a modest number of chickens, I think I would have gone that route. Just be honest with them on how many chickens it will adequately hold. I still get upset seeing those tiny coops at the local farm stores being sold to house twice as many chickens as anyone here on BYC would recommend.We are designing a new coop this year. We bought plans from someone for the first one, and it has served us okay for four years, but never did hold the amount of chickens they said it would.
I watched a lot of YouTube videos, checked out books from the library, and read a lot on BYC forum and asked a bunch of questions before I started my coop build. So far, I am pretty happy with my build after 7 months. The real test will be to see how I like it after this first winter. I agree that we all are somewhere on a learning curve.