Walmart offers the Sceptre 54.6" 4K Flat LED Ultra HD Television, model no. U550CV-U, for $259.99 with free shipping. That's tied with last week's mention and the best deal we could find by $60. It features a 3840x2160 (4K) native resolution, USB 2.0 port, and four HDMI inputs.
You very likely are putting your laptop battery into an early grave.