Comment by unfocso

Also note: LCSC sells PY32 Arm Cortex-M0 (PY32C642-C) for half the price (0.06$) of the cheapest CH32 [CH32V005D6U6] (0.11$). Given it has half the RAM, but price matching yields a better chip for less or the same money.

STMicroelectronics also launched the STM32C0 series that is still quite cheap @ ~0.35$/piece.

However, the prices on aliexpress all mishmash so giving a correct quote is impossible as the same chip is sold at wildly different prices by different sellers.