Amazon.com: TP-Link Powerline WiFi Extender - Add-on Single Adapter, Ethernet over Powerline, Plug & Play, Compatible with all TP-Link powerline adapters with different speed, AV600 with N300 WiFi(TL-WPA4220) : Everything Else
TP-Link's Powerline Extender Kit routes internet through existing electrical wiring: $34 (Reg. $48)
TP-Link AV1000 Gigabit Passthrough Powerline ac Wi-Fi - Dual band 802.11ac Wi-Fi, HomePlug AV2 Compliant, 1x Gigabit Ethernet Port, Up to 300 Meters Powerline Range - TL-WPA7617 at TigerDirect.com