Aeon Labs Z-Wave Smart Energy Switch Minimote DSA03202-V1 for $19.95
https://www.buydig.com/shop/product/AEONMINIMOTE/Aeon-Labs-Z-Wave-Smart-Energy-Switch-Minimote-DSA03202-V1
There are in-wall switch ($44.95), range extender ($29.95) and Home Energy Meter ($19.95) on sale as well.