Ustation via eBay offers this TPU Rubber Ultra-Thin Transparent Skin Case for iPhone 6 in five colors (Black pictured) for 99 cents with free shipping. (58tuanguo via eBay offers it for the same.) That's tied with our January mention and the lowest total price we could find by a buck. It features TPU construction.

Note that this item ships from Hong Kong and has an estimated delivery time of two to six weeks.