Use MeritLine coupon code MLCW16SN
MeritLine has this Trident Cyclops Case for iPhone 5 for $39.95. Use the coupon code and the price drops to $18.95. Amazon.com sells the same case for $22.
The case features an impact-resistant silicone inner-sleeve, hardened polycarbonate outer framework, built-in screen protector and dust filters. Shipping is free.