AtholCoop is right - no offense to what you ordered but I don't think you are going to be happy with it. I looked at something like that at our local farm store and it's cheaply made and not nearly big enough - especially the run area. It said it could house 4 large fowl. Two maybe - tops, but not 4. One of the biggest complaints about the current coop we have is that I can stand straight up in the run or coop. No offense to anyone here but I can't see the draw to something that low to the ground. Everybody is different but for us, we get snow deeper than that coop and those ground coops would literally disappear in the winter. LOL!
Personally I'd do a little more searching. If you're getting baby Silkies, you have a little while until they can go out into the coop anyway. Keep looking on CL for something local. Hopefully the people you contacted can do something in your price range. We had a local college student build our new (2nd) coop and it was a great deal. 4x6x6 for about $400