Where I can get a brand new Arris TM 3402, not at Best Buy and the one in Amazon is not new.

Trying to upgrade my Gigabyte Modem/router with telephone Line, Cox website only refers to the Arris TM 3402 for Gigablast and phone line. But by manufacture that model is obsolete, which live me with no options. So Cox where I can get a brand new Arris TM 3402?