My guess is shipping from china to the US for a pre assembled coop of that size will easily be in the hundreds (200-500) even by 6-8 week ship type shipping if in bulk. Shipping a 4 foot by 4 foot by 1 foot box just 3000 miles across the US cost me nearly $100. An assemble at home type or just coop plans may be better shipping wise.
I think the reason the OP is trying to test the market for her coops is because of such things like the eglu, henspa, and so on, which are small coops that come with hefty price tags. Many of us on here are do it your self types and will take the time to build things from the ground up, but with $700 eglus still selling, it's a niche market.
As for the silkies, they are the black skin chicken, or black bone chicken used in medicinal soups believed to be healthy for the body. My mom would turn all my girls in to soup if I let her.