TomTop offers the X96 Kodi 4K WiFi 16GB Smart Android TV Box for $43.99. (Choose "United States Warehouse" under "Ships From" and "16G" under "Rom" to see this price.) Coupon code "4V2248" cuts that to $39.99. With $2.65 for shipping, that's the lowest price we could find by $2, excluding the below mention. Features include an Amlogic S905X 2GHz quad-core processor, 2GB RAM, 16GB eMMC storage, 4K support, 802.11n wireless, Ethernet, HDMI, USB, microSD cart slot, and Android 6.0 OS (Marshmallow).
Note: The countdown timer on the product page does not reflect an actual expiration time and resets daily.
Don't mind waiting on your deal? Geekbuying offers it for $39.99 with free shipping. It ships from China and requires two to four weeks to arrive.