USAPowerPros via eBay offers this USB Wall & Car Charger Set for $4.24 with free shipping. That's tied with our mention from a week ago and the lowest total price we could find for a comparable set by $3, outside the mention below. (For further comparison, we saw a refurb for $3 less last winter.) It includes a 1-amp wall charger and 0.7-amp car charger, each featuring a USB connector.

A close price: WITCHINA via eBay offers a similar set for $4.95 with free shipping.