B&H Photo Video offers the Chromecast Ultra Streaming Media Player for $59 with free shipping. (Google Store and Target have it for the same with free shipping.) That's the lowest total price we could find by $10. It features HDR and 4K Ultra HD Video, 802.11ac, HDMI, works with streaming apps, and mirrors the Chrome browser or Android device.
A close price: Best Buy via eBay has it for $59.99 with free shipping.