And I have gotten my base IoT node down to about 2.50$. How? Arduino Nano ($1.80) nRF24L01+ (0.63$) Both from Aliexpress. Combine it with MySensors library an

And I have gotten my base IoT node down to about 2.50$. How? Arduino Nano ($1.80) nRF24L01+ (0.63$) Both from Aliexpress. Combine it with MySensors library and off you go. For secure connections, use the USB-serial gateway, change the default channel, turn on encryption as well as signing support. I use Node-red to get the data and do stuff with it.