Altatac via eBay offers the refurbished Apple MacBook Air Broadwell Core i5 1.6GHz 11.6" Laptop for $549.95 with free shipping. That's $100 less than our September mention, an all-time best, and $349 under the lowest price we could find for it new. It features an Intel Core i5 1.6GHz Broadwell dual-core processor, 11.6" 1366x768 LCD, 4GB RAM, 128GB flash storage, webcam, 802.11ac wireless, Bluetooth 4.0, USB 3.0, Thunderbolt, and Mac OS X 10.10 Yosemite.

A 90-day warranty applies, although it's unclear who backs it.