A phone parts distributor has gotten a hold of iPhone 5S front panels, and says these are about to cost $240 a pop. They have also been snapped next to the iPhone 5 front assembly to visualize the differences...
Source: http://www.phonearena.com/news/Apple-iPhone-5S-front-panel-snapped-next-to-the-iPhone-5-one-sporting-a-new-ribbon-cable_id46109
Source: http://www.phonearena.com/news/Apple-iPhone-5S-front-panel-snapped-next-to-the-iPhone-5-one-sporting-a-new-ribbon-cable_id46109