I don't know about that - I can pick up a ESP8266 dev board for under $5 individually on mouser - I feel like I should be able to get that cost down significant

I don't know about that - I can pick up a ESP8266 dev board for under $5 individually on mouser - I feel like I should be able to get that cost down significantly if I am building millions. I am not an expert in manufacturing at all but it seems like I should be able get a small enclosure and battery for under $1.50 in high enough quantities.