That's a great coop! Simple and light is a great way to go. Mine's nearly done since my four Australorp pullets are nearly ready to go outside. I'll be glad to get them outta my bathtub!! I resisted the urge to overbuild, because I want it portable and I'm poor right now! made a very simple 4'x8' run. It's ultra-light, made of 2x2's and 1x2's with lots of home-made sheet metal corner bracing.
I spent $10 on wood. The wire and everything else was from my junk collection. Oh-- I also bought surplus paint from a thrift store for two dollah.