Sigma 50mm f1.4 DG HSM ART for $850 with extras (C/N/A/S)

Prime time now, the Sigma 50mm f1.4 DG HSM ART is going for $850 with some extras in the Canon, Nikon, Sony and Sigma SLR mounts. At B&H Photo you get 4% promotional rewards (= $34~), while at Adorama you get a handful of free accessories and a 3-year NewLeaf spills-n-drops warranty. No freebies at the moment at Amazon.