may I ask where can I buy Pi Zero for 5 dollars? Even on Aliexpress (perhaps I wrongly assume it's the cheapest place to buy) there options start from $15 and up https://www.aliexpress.com/wholesale?catId=0&initiative_id=S...
I'm not trying to invalidate your argument in any way, just genuinely curious. Also, does anyone know the actual production cost of such device?