I'd just buy Antminers directly from Bitmain when they're in stock, like right now get the latest S9 from them for 1288 USD. Sure beats $2000+ on eBay, if you're willing to wait a month
FYI if you don't already have an Antminer beware they're loud as F%^&#!! & run hot! My wife let me put mine in the garage but we're much happier now with the gentle hum of GPU rigs