Walmart offers the refurbished TCL 54.6" 4K 2160p LED-Backlit LCD Ultra HD Roku Smart Television, model no. 55US57, for $309 with free shipping. That's $31 under our Black Friday mention of a new similar TV and the lowest total price we've seen for any TCL 55"-class 4K Roku TV. (It's also $191 under what you'd pay for a similar model new today.) It features a 3840x2160 (4K, 2160p) native resolution, 802.11ac wireless, built-in Roku TV (with access to Netflix, Youtube, Hulu Plus, more), USB, and four HDMI inputs.
No warranty information is provided.