I have 4 chickens and the cheapest/easiest way I found to make a run was a 10x10 dog kennel. Each chainlink panel is 6' tall and 10' long, so they've got 100 sq ft to play in. Their raised 4x4 house is inside it, so they can go under/in/on top of the house. I can't free range because of predators, but they seem happy enough with the space. I covered the bottom half of the chainlink with hardware cloth then ran it onto the ground to keep dogs/predators out, and covered the top half (and actual roof of pen before I put it under my deck) with bird netting. My local co-op has the kennels for $200, so the entire run cost me about $250 with the cloth. I've got a full walk-in door, I can move it easily if need be, and it was very easy to set up.