TomTop offers this H8R 4K Ultra HD WiFi Action Sports Camera in four colors (Silver pictured) bundled with a Wrist Remote for $42.99 with free shipping. (Be sure to select U.S. Warehouse to see this price.) That's $12 off list and the lowest price we could find. Features include a 2" LCD, up to 4K video recording at 60fps, 12-megapixel CMOS sensor, 170° wide-angle lens, WiFi, microSD card slot, and housing that's waterproof up to 98 feet. (The wrist remote is not waterproof.) It comes with multiple mounting options.
Note: The countdown timer on the product page does not reflect an actual expiration time and resets daily.