Amazon offers the Aukey 3600mAh battery with short Apple-certified MFi Lightning cable for $9.99 shipped. The battery will fully charge an iPhone 6/s or plus or get you hours of additional life on an iPad or iPad Mini. This battery charges with Apple Lightning too so you don’t need the Micro-USB cable here. It gets 4/5 star reviews from Amazon readers. The $10 price is notable here because its half of what Apple charges for a MFi cable alone and a tenth of what Apple charges for a battery case of smaller capacity.
Also, if you are just looking to buy bulk Lightning cables, Cadmium Cables offers a 3-pack of 3-foot Lightning cables for just $8.48 shipped. At under $3/cable, that’s near an all-time low and these get 3.9/5 star reviews and come with a money back guarantee. Note that some reviewers question if these are Apple Certified Lightning cables while still saying they work as advertised.