BuyDig offers the Sigma 17-50mm f/2.8 EX DC OS HSM Lens for Canon, model no. 583101, for $568.99. Coupon code "ZOOM150" cuts it to $418.99. With free shipping, that's tied with our mention from two weeks ago as the lowest total price we've seen for this lens. (It's also a current price low by $150.) Features include FLD glass elements, anti-shake, 11" focus, and 1.5x magnification.