LaViewSecurity.com has the 4K IP 4- camera security system on sale for $669 - 20% Off w/ code SPD20 = $535.2. Shipping is Free. Tax in CA.
https://www.laviewsecurity.com/8-channel-4k-nvr-4-2-rx-453.html
Also available
6-camera 4K security system w/ 2TB - $679.2 after code SPD20
8-camera 4K security system w/ 2TB - $863.2 after code SPD20
https://www.laviewsecurity.com/8-channel-4k-nvr-4-2-rx-453.html
Also available
6-camera 4K security system w/ 2TB - $679.2 after code SPD20
8-camera 4K security system w/ 2TB - $863.2 after code SPD20