As one of its daily deals, Amazon offers the SanDisk iXpand 64GB USB Flash Drive with Lightning Connector, model no. SDIX-064G-G57, for $49.99 with free shipping. That's the lowest total price we could find by $20. It works with iPhones/iPads with a Lightning connector and iOS 7.1 and higher.

Also available is the SanDisk iXpand 128GB USB Flash Drive with Lightning Connector, model no. SDIX-128G-G57, for $79.99 with free shipping. That's the lowest total price we could find by $20. Both deals end today.