Best Buy via eBay offers the Sharp 49.5" 4K HDR Flat LED UHD Smart Television, model no. LC-50LBU591U, for $299.99 with free shipping. That's $100 off list and tied with our mention from a month ago as the lowest price we could find. (For further comparison, we saw it for $3 less in August.) It features:

3840x2160 (4K) native resolution

WiFi w/ Roku content streaming (Netflix, Youtube, Pandora, and more)

USB and 3 HDMI