Adorama via eBay offers the GoPro HD HERO4 Black Edition 4K Action Camcorder, model no. CHDHX-401, for $399 with free shipping. That's a buck below our mention from five days ago and the lowest total price we could find by $60. It features 4K video recording, up to 12-megapixel photos at 30 fps, waterproof housing (up to 131 feet), WiFi, and Bluetooth.