Nextmall via Amazon offers Prime members the Turata Waterproof Dry Bag Case for iPhones and Samsung Phones, model no. 5162610, for $5.99 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, it costs an extra $5.99.) That's $14 off and the lowest total price we could find. It fits phones up to 6", is waterproof up to 100 feet, and comes with an armband.