Staples B&M: Mophie Space Pack 16GB (iPhone 5/5s/SE) $11.50, on clearance YMMV
Thread DetailsLast Edited by annie930ny October 2, 2016 at 08:28 AM
For reference, Amazon currently has it for $28.51. If you're looking for more space, Amazon sells the 32GB model for $32.98, a much better value than the 16GB if you need more storage.
This was originally $150 when originally released.
The Mophie Space Pack adds a 1700 mAh battery (more than doubling battery life) and adds a 16GB partition accessible through their app, which works well with videos and photos "sync'ed" from the phone. I've loaded videos and music to the Space Pack through both the micro-USB cable (the Space Pack shows up like a flash drive on a computer) and via WiFI (through a web client interface accessible via IP address from a computer on the same WiFi network). Music is more of a pain and apps cannot be loaded on this 16GB partition. This does add thickness, length and some weight to my $200 unlocked iPhone SE from US Cellular on RingPlus.