$32 for a Samsung Galaxy S3 External Battery Case from Google Offers. Normally around $70 bucks, listed as 59% off. Cheers!
https://www.google.com/offers/home#!details/5ef21ba262f408c1/XC3C201O8SE3YYO9;r=IWRldGFpbHMvNWVmMjFiYTI2MmY0MDhjMQ%3D%3D
https://www.google.com/offers/home#!details/5ef21ba262f408c1/XC3C201O8SE3YYO9;r=IWRldGFpbHMvNWVmMjFiYTI2MmY0MDhjMQ%3D%3D