I just emailed bitmain customer service about buying them. No answer after 48hours.

They almost never answer that e-mail.. they read it and do what is needed to correct.
Also, Canadian here, I've had two orders from bitmain both came in with in 5 days of pay and all units were in perfect working order. Will probably buy more soon, although I hear roomers about a 28nm product from bitmain.. might just hold on my 4 and wait.