Massdrop offers the Grifiti Lichen USB Charger 2-Pack for $14.99 plus $2.28 for shipping. That's the lowest total price we could find for two by $3. Available as a Lightning or Micro USB connector, it charges from any USB port and will transfer data when connected to a computer. Deal ends February 4.

Update: grifitiproducts via eBay offers the Micro USB connector version 2-pack for $15 with free shipping.