Qualitycellz via eBay offers the open-box Unlocked Apple iPhone 5S 16GB GSM Smartphone in Black for $549.99 with free shipping. That's tied with our mention from two weeks ago as the best price we've ever seen for an unlocked iPhone 5S. (It's a current price low by $99.) Deal ends June 12 at 11 am ET.

A 90-day warranty applies, although it's unclear who supports it.