Walmart has the Samsung 50" 4K HDR Flat LED Ultra HD Smart Television (UN50NU6900BXZA) for $328 with free shipping. Features 3840x2160 (2160p) native resolution, WiFi, Smart TV apps (YouTube, Netflix, Hulu, etc.), HDMI.
Walmart has the Seiki 65" Class 4K Ultra HD (2160P) Smart LED TV (SC-65UK700N) for $450 with free 2-day shipping. Features 3840x2160 resolution, 60Hz refresh rate, 1000:1 contrast ratio, Built-in Wi-Fi, 3x HDMI, 2x USB, 178° viewing angles.
Amazon has the Samsung 82" 4K HDR Flat LED Ultra HD Smart Television (UN82NU8000FXZA) for $1999 with free shipping. Features 3840x2160 (4K) native resolution, 120Hz refresh rate, UHD dimming, and HDR Plus, 2 USB, & 4 HDMI inputs.