Groupon offers the Otterbox Preserver Series Case for iPhone 5/5S in four colors (Carbon pictured), model no. 77-36355, for $24.99 plus $3.99 for shipping. That's $5 under our mention from last fall and the lowest total price we've seen. (It's a current low by $11, outside of the mention below.) This case is waterproof up to 6.6 feet and features a built-in screen protector.

A close price: A4C offers it for $29.95 with free shipping.