Pictured above is a new Millwood area chicken tractor made from a discarded shipping crate. You can barely see it because of the shadows, but the crate is on wheels so it can be moved around, along with the PVC framed run. The birds can feed/mow and fertilize one section of grass and then do the same to the next section. If you don't move the run around their potent chicken poo will eventually kill the grass. They said it cost them around $300 with all of the hardware. They have two meat birds and some laying hens.
Send me pics of your chicken coop or tractor as part of the View from Your Garden Series.