The TP-LINK HS100 Smart Plug drops from $29.99 to $22.99 when you apply the code EMCRFRE56 in your cart at Newegg. Plus, the shipping is free. This is the lowest price we could find for one by $2. Once connected to your home WiFi network, these smart plugs can be remotely controlled from anywhere using a smartphone or tablet and can be voice-controlled using an Amazon Echo with Alexa. Note: This model does not have energy monitoring. There's no sales tax (except CA, IN, NJ, and TN).