iTech Deals offers the refurbished 3-lb. Apple MacBook Air Intel Ivy Bridge Core i5 1.7GHz 13.3" Laptop for $407.99 with free shipping. That's $41 under our mention from two weeks ago and the lowest price we could find for a refurb today by $31, excluding the below mention. It features an Intel Core i5-3317U 1.7GHz Ivy Bridge dual-core processor, 13.3" 1440x900 LED-backlit display, 4GB RAM, 64GB SSD, 802.11n wireless, Bluetooth 4.0, Thunderbolt, USB 3.0, backlit keyboard, 4-cell battery, and Mac OS X 10.9 (Mavericks). Deal ends October 5.

Note: No warranty information is provided.

A close price: Tanga offers a refurb with Mac OS X 10.11 (El Capitan) pre-installed for $409.99 with free shipping. (A 90-day warranty applies, but it's unclear who covers it.)

Update: iTech Deals has since dropped its price to $399.99.