Adorama via eBay offers the Sigma 10-20mm f/4-5.6 EX DC HSM AF Super Wide Angle Zoom Lens for Canon EOS DSLRs, model no. 201101, for $329.99 with free shipping. That's $50 under our mention from two weeks ago and the lowest total price we've seen. (It's a current price low by $20.) It features three SLD glass elements, a minimum focusing distance of 9.4", and angle of view of 102.4° to 63.8°.