This deal from Adorama is live again: the Sigma Contemporary 150-600mm f/5-6.3 DG OS HSM for Canon is now $789.00. You also get a free Sigma USB Dock for Canon Lenses ($59 of value). Free shipping is included.
With the free Sigma USB Dock for Canon Lenses (about $59 of value), this is a great deal versus the regular price of $989. Sigma lenses purchased from authorized dealers come with a 4-year Sigma USA warranty. Nikon mount is also available.