IME with buying new bitmain miners (with the exception of the E3) the price always drops dramatically.  I bought into the A3s paid 2500 for first 980 for the second and now they are 520 (perhaps the fork threat is causing this) but the point is, buying in at the beginning and hoping ROI is fairly difficult to achieve for me so far.  I am getting close to A3 ROI after 2 mos, but if I had to do it again, I'd prolly wait until batch 2.

In fairness to bitmain, they do compensate with extremely generous coupons, that I appreciate.