Yugster offers the refurbished 2.4-lb. Apple MacBook Air Intel Core i5 1.6GHz 11.6" Laptop, model no. MC969LL/A, for $549.99. Coupon code "FreeYugBuck" cuts the price to $548.99. With $5 for shipping, that's $646 off and the lowest total price we could find, although we saw a refurb for $14 less last week. It features an Intel Core i5 1.6GHz Sandy Bridge dual-core processor, 11.6" 1366x768 LCD display, 4GB RAM, 128GB SSD, AirPort Extreme (802.11n wireless), Bluetooth 4.0, Facetime camera, Thunderbolt port, USB, and Mac OS X 10.9 Mavericks (it includes an upgrade to 10.10 OS Yosemite). Deal ends December 25 at 4 am ET.
A 90-day warranty applies, but it's unclear who backs it.