Walmart has the JVC 49" 4K UHD Smart TV w/ Chromecast (LT-49MA875) for $250 with free shipping. It features a 3840x2160 (4K) native resolution, 802.11ac wireless & Bluetooth 4.2, built-in Chromecast (with access to Netflix, YouTube, Hulu, more), 3 HDMI inputs, USB 2.0.
Walmart has the Samsung 55" 4K UHD HDR Smart LED TV (UN55MU800DFXZA / UN55MU8000FXZA, 55" 2017 model) refurbished for $450 + $20 shipping fee = $470 shipped. Features 3840 x 2160, HDR10 support, Motion Rate 120, Built-in Wi-Fi, Samsung Smart Hub, 4 x HDMI, 3 x USB.
Walmart has the Vizio D50-F1 50" 4K UHD HDR Smart LED TV (2018) refurbished for $276 with free shipping or in-store pickup. Retail price: $430. Features 3840 x 2160 (4K UHD), 120Hz Effective Refresh Rate, Built-in Chromecast, Built-in Wi-Fi, Ethernet, V8 Octa-Core Processor, Full Array LED 3 x HDMI.