Cell.Expert via eBay offers the Carbon Fiber Pattern iPhone 6 Plus Hard Case Cover in Black for $1.34 with free shipping. (A 4.7" iPhone 6 case is available for a penny more and a Silver iPhone 6 Plus is available for $1.52.) That's tied with last week's mention, and outside of other eBay vendors, the lowest total price we could find by $4. It's made of carbon fiber and leather.
Note: This item ships from mainland China and may take three to eight weeks to arrive.