Canon cuts up to $550 off select new and refurbished EOS digital SLR cameras, lenses, and PowerShot digital cameras. Shipping adds $5, or get free shipping on orders of $200 or more. A 1-year Canon warranty applies to all refurbs. A couple best bets, with price comparisons to new units:
Adorama via eBay offers the Canon EF 100-400mm f/4-5.6 6L IS USM Telephoto Zoom Lens, model no. 2577A002, for $1,299 with free shipping. That's the lowest total price we could find by $195. It features 17 elements in 14 groups, a minimum focusing distance of 5.9 feet, and angle of view of 24° to 6°.