With a completely brand new coop, new materials, and many good quality materials I am at about $2000. I still need to do a few thins like siding and metal roof though, so that price will go up. I know others that have spent much more as well. It just depends on how you like to do things. I am building everything from scratch, so it needs to be new. And If I am going to build it I want it to last for a long time, so I use good materials. I don't like having to rebuild things. Even a coop. Here is what I have at present.
6'x8' coop with an attached 6'x8' enclosed sunporch. 24'x24'x8' run.
Ours cost about $900, closer to $1000 w/ waterers, feeders & the nesting boxes (which came later). It's 8x8 (x12?) and a run that is 8x18 (?). You can see the beginning stages at my BYC page (link under my name).
The cost is relative. My family made fun of the cost. Then I had to rag on my sis for spending $800 on a pair of binoculars, & dad the same on a camera. A building as big as we built it, is worth way more than a pair of binos that can be dropped & broken.
We are in the process of finishing up House #2 -- it's a playhouse design -- for a friend. We have about $500 in materials into it. B.U.T. it's fully insulated, has a roofed run, all green-treated lumber, hardwired electricity (outlet and heat lamp fixture), and a large window. It think we did pretty good! And all materials are new except for the window.
Okay - Coop #1 cost $30. I built inside my barn - in a corner and utilized an existing door and window. Used old road signs and recycled lumber and nails. Run cost about $100. 30' x 10'. Coop #2 cost about $35-45. Hardware cost the most. I used a lot of stuff I had around. Free and recycled...freecyled. Only the best thing ever!