My husband built our coop and we used a lot of materials we had around but when you factor in how many hours he spent andvwhatbhe normally charges per hour it comes to an $8000 coop...haha...he really enjoys his projects.
That being said when I first looked for coops to buy I was thinking of spending $400-700 for 4-5 LF hens. When I saw the coops in person they were so tiny and looked like such a rip off.
When I look at your coop with the size, design, features, etc. I would pay at least $1500 but I am know for being a tightwad.
We actually got a lot of our ideas from your great coop. You can see pics in our blog.
Maybe you can design something a bit smaller for the smaller flock owner like me who may not be quite ready to commit to a $2000 investment and 15 chickens...like a $800 coop for 5-6 chickens. We have a local builder that sells in the $700-1200 range and the coops are cute but tiny.