I'm trying to decide on a plan for a coop. I currently have four chickens but think it might be wise to build slightly bigger in case I decide to get more chickens in the future (maybe large enough for eight?). Money is definitely a consideration but it'd be nice to have a coop with a walk-in run. If you went with this design, how much would you say it cost to build so big? I guess it isn't a "must", but I'd love to be able to get in there with my daughter and visit with the girls as often as possible.