Deal Train via eBay offers the factory-refurbished Apple MacBook Air Broadwell Core i5 1.6GHz 11.6" Laptop for $639.99 with free shipping. That's $80 under our mention from January and the best price we've seen for this laptop. (It's also a low for a refurb now by $150.) It features an Intel Core i5-5250U 1.6GHz Broadwell dual-core processor, 11.6" 1366x768 LED-backlit LCD, 4GB RAM, 256GB SSD, 802.11ac wireless, Bluetooth 4.0, Thunderbolt port, and OS X Mavericks.
A 1-year Apple warranty applies.