Yeah WCH make some really cheap chips. Apart from ch552, there is also a family of BLE chips such as ch571f that is much more efficient than ESP32 (from online sources) and is very cheap. You can get the chip for half a dollar (https://www.aliexpress.com/item/1005005974200193.html) and a development board for less than 3 dollars (https://www.aliexpress.com/item/1005005974200193.html). When I bought it on taobao, it is actually around 1.3 dollars.
The downside is that software support does not exist (yet), so will have to try and make a firmware for it. I haven’t yet found time as I was working on manifold things.
Nice, I can buy ch582f dev board for 2 dollars. Still very cheap!