Newegg offers the Zyxel AV Powerline Wall Mount Ethernet Pass-Through Adapter 2-Pack, model no. PLA5215KIT, for $50.65 with free shipping. (Amazon and Walmart charge the same.) That's $4 under our May mention and the lowest total price we've seen. (It's also a current low by $13.) These adapters use your existing electrical outlets to create a secure high speed building-wide network. They support up to 600Mbps data transfer rates.