Instant Replay Electronics via eBay offers the refurbished 2.38-lb. Apple MacBook Air Intel Core i5 1.6GHz 11.6" Laptop, model no. MC969LL/A, for $549.99 with free shipping. That's $49 under our refurb mention from earlier this month and the lowest total price we've seen for a refurbished MacBook Air with a 128GB SSD. It features an Intel Core i5 1.6GHz Sandy Bridge dual-core processor, 11.6" 1366x768 LED-backlit display, 4GB RAM, 128GB SSD, AirPort Extreme (802.11n wireless), Bluetooth 4.0, Facetime camera, Thunderbolt port, and Mac OS X 10.9 Maverick.

A 30-day warranty is included, but it's not clear who backs it.