Flamboyant Mouse via eBay offers the Mophie Juice Pack Plus 2000mAh Battery and Case for iPhone 4 in five colors (Black pictured) for $52. With free shipping, it's the lowest total price we could find in any color by $47. This 2000mAh battery pack and case, purports to more than double the battery power of the stock iPhone battery, and features a standby/charging toggle switch, protective rubberized case, status LED, and more