Walmart offers preorders of the Polaroid 55" 4K HDR Flat LED Ultra HD Smart Television, model no. 55T7U, for $239.99 with free shipping. That's the best deal we could find for this model by $210 and the second-lowest price we've seen for any new 55"-class 4K Smart TV. It features a 3840x2160 (4K) native resolution, smart TV apps (including Netflix, YouTube, Vudu, more), and three HDMI inputs.
Note: It's expected to ship by January 3, 2019.
There are many ways to get cheap and even free services and goods after reaching a certain age.