What discount? And why would Bitmain charge less for blades use in an S1 upgrade vs an S3 purchase?
Maybe the cost of frame, controller, and shipping weight/volume is not negligable?
As mentioned previously in this thread (although not quoted), those compose of perhaps 10% of the price, or approximately $40. Why wait around or hang your hopes on getting an upgrade kit to save $40? Not to mention an old S1 is worth about $150 or so on the open market, and you lose the ability to sell it if you upgrade.