Amazon Warehouse Deals has OtterBox Commuter iPhone Cases (Used: Very Good - Like New) on sale. Shipping is free with Prime or if you spend $35 or more.

• OtterBox Commuter iPhone Cases for 6+/6S Plus
  • Used: Very Good $6.92
• OtterBox Commuter iPhone Cases for 6/6s
  • Used: Very Good $5.14

No longer available:

• OtterBox Commuter iPhone Cases for 6+/6S Plus
  
  • Used: Like New $7.34
• OtterBox Commuter iPhone Cases for 6/6s
  
  • Used: Like New $5.45