I build 4'X4'X4' OSB boxes (with a slanted roof), I put on pretty much either 4'X6' or 4'X8' runs, (2X4's as the base) which are about 5' tall. Then you can split down the center with chicken wire and have two pens for 2-5 standards or bantams.
All my pens are movable, I put wheels under the coop in the back. I can upload pictures sometime if you are interested.
My coops go from 80-150$ apiece on average. And remember, less is more. I have learned the hard way many times when building coops, use only what you need to keep the chickens safe, as if you over-use materials they become heavy and hard to move.