Refurb Apple iPhone 5 16GB for Sprint (no contract) for $520 + free shipping
newegg offers the refurbished, no-contract Apple iPhone 5 16GB Smartphone for Sprint, model no. MD656LL/A, for $519.99 with free shipping. That's the first refurbished iPhone 5 we've seen that doesn't require a contract. (It's $129 less than buying a new unlocked model from Apple, but those won't work with Sprint.) It features an Apple A6 processor, 4" 1136x640 Retina display, 8-megapixel iSight camera, 1.2-megapixel FaceTime HD camera, 1080p video capture, 802.11n wireless, Bluetooth 4.0, and more. Deal ends March 21.
A 90-day warranty applies, although it's unclear who backs it.