This hot clearance deal at Best Buy is back: the Sigma Art 24-35mm f/2 DG HSM for Canon is only $399.99 — while quantities last! Compare with a regular price of $999 for this lens. This sold out quickly last time.
Note that Best Buy‘s listing says this is a “DC” (crop-sensor) lens — this appears to be a mistake; the UPC and pictures indicate it’s a “DG” lens that can be used on a full-frame EF mount. (Sigma does not make a Art 24-35mm DC lens.)