I Love Dooney via eBay offers the Dooney & Burke Madison Signature Giant Sac in five colors (Black pictured) for $109.99 with free shipping. That's $158 off and the lowest total price we could find. It features an adjustable strap, six interior pockets, and a zipper closure.
REI Garage offers the Mountain Hardwear Tonga Short-Sleeve Dress in Blue, Black, or Raspberry for $44.73. Opt for in-store pickup to avoid the $5.99 shipping charge. That's the lowest price we could find by $2. It's available in sizes XS to XL, although not in all size/color combinations.