We're just finishing up a 8x12 coop, eight foot walls on one side, ten on the other (don't ask, we're crazy, just accept it). Cement pad, J hooks, exterior OSB that looks like siding, interior plywood, insulation, electricity (for lights, outlets, water heaters, outdoor lights--like I said, nuts, but I'm gonna love this), people door, three pop doors and lots of windows (super cheap), We're putting in a loft at 7 foot high over the taller part of the coop for storage and I'm also storing feed and my gardening tools out there. We don't have the run done yet, but with everything (which cost more every time dh got a brilliant idea) including the run, we're going to be stretching close to $2000. My MIL keep asking what it's costing because she wants us to build her a little bitty house, but I won't answer--and no way are we building a house, not a chance! lol
Once my silkies and cochins are old enough to start laying I'll split the pen space into three (thus the three pop doors) and the run so I can have pure eggs for sale and hatching.
My next coop is going to cost me less than $50--I swear it! I'm already gathering supplies. lol