Yugster offers the LifeProof Samsung Galaxy S3 Nuud Case for $9.97. Coupon code "FreeYugBuck" drops it to $8.97. With free shipping, that's a buck under our mention from last month and the lowest total price we've seen. (It's a current low by $7, excluding the mention below.) It's fully submersible up to 6.6 feet, and also claims to be drop-resistant, dirt-proof, snow-proof, and shock-proof. Note that the countdown timer on the product page does not reflect an actual expiration time and resets daily.
A close price: The Good Blokes via eBay offer it for $9.50 with free shipping.