Amazon offers the Nokia Lumia 520 4G 8GB Windows 8 Prepaid Smartphone for AT&T GoPhone for $19.99 with free shipping. (Non-members can spend $35 or more to bag free shipping; otherwise it adds $6.70.) That's $9 under our mention from two days ago and the lowest total price we've seen. (It's a current low by $9.) It features a 4" 800x480 IPS touchscreen LCD, Qualcomm Snapdragon 1GHz dual-core processor, 512MB RAM, 8GB internal memory, 5-megapixel rear camera, microSD, micro USB, Bluetooth 4.0, and Windows Phone 8 OS.
Orders placed via Prime by December 22 are guaranteed for Christmas delivery.