Aukey Direct via Amazon offers its Aukey 3.1-amp Dual USB Port Solar Charger, model no. PB-P2, for $47.99. Coupon code "TEEC24N4" cuts that to $39.99. With free shipping, that's $50 off list and the lowest total price we could find. It features PET laminated solar panels, a foldable design, and a USB charging cable.