Dell Home offers the LG 48.5" 4K HDR IPS LED-Backlit LCD Ultra HD Smart Television, model no. 49UJ6300, bundled with a $50 Dell Gift Card for $399.99 with free shipping. Assuming you'll use the gift card, that's the lowest price we could find by $97, although we saw it for $330 three weeks ago (without a gift card). It features a 3840x2160 (2160p, 4K) native resolution, 4K upscaling, active HDR, 802.11ac wireless, webOS 3.5 (with access to Netflix, Hulu Plus, YouTube, more), USB, and three HDMI inputs.

Note: Kohl's also has it, with $75 in Kohl's Cash, for $399.99 via in-store pickup. (Stock varies notably by ZIP, however.)