Altatac via eBay offers the refurbished Apple MacBook Air Intel Ivy Bridge Core i7 2GHz 11.6" Laptop for $509.95 with free shipping. That's the lowest price we could find for a refurb by $59. It features an Intel Core i7-3667U 2GHz Ivy Bridge dual-core processor, 11.6" 1366x768 LCD, 4GB RAM, 128GB SSD, Thunderbolt, and OS X 10.7.4 (Lion).

Note: A 90-day warranty applies, but it's not clear who backs it.