JustDeals offers the IOGEAR GearPower Edge Rechargeable Protective Case Combo for iPhone 4 / 4S, model no. GMP2004P, for $14.77 plus $5 for shipping. That's the lowest total price we could find by $18. It features a 1,700mAh lithium-polymer battery pack, kickstand, battery capacity indicator, wearable case, charge and sync cable, and more. Deal ends May 31.