Comment by zoobab

"Microcontrollers like the Puya PY32 Series (e.g., PY32C642, PY32F002/F030) can cost in the $0.02 - $0.05 range"

LCSC says between 6 and 8 cents in volume:

https://www.lcsc.com/product-detail/C5292058.html

500+ $ 0.0802 2,500+ $ 0.0727 5,000+ $ 0.0682"