I was also tempted to use new IOT amazon buttons with the IOT AWS offering ( https://aws.amazon.com/iot/ ), but after looking a bit deeper, the free limit is not that high. Instead, I bought ESP8266 Wemos D1 mini for $4 each. Instead of AWS IOT I used Google Firebase and I have to admit, it works pretty sweet for me. IFTTT, Siri integration and all.

https://piszek.com/2015/06/24/smartpi/