Ebay offers CleverMade Pacifica 20-Can Backpack Cooler for $17 (reg $34.98) with free shipping.

Product Description:
Made from recycled materials equivalent to 8 plastic bottles. Thick insulation and leak resistant design. Easy to carry with padded shoulder straps and chest strap. Mesh side pockets can fit most water bottles. Sleek design that's great for beach trips hikes and picnics.CleverMade 20-Can Pacifica Backpack Cooler