XPU Labs, a subsidiary of AnalogLamb, has designed three inexpensive “Polos” development boards based on WCH CH32VXX RISC-V microcontrollers with pricing starting at just $1.99.
The three development/breakout boards have the same form factor and only differ in the specific RISC-V MCU used with three parts selected: the 48 MHz CH32V003F4U6 microcontroller, the 144 MHz CH32V203F8P6 MCU, and the CH32V305FBP6 that’s similar to the former but add more memory (32KB) and flash (128KB). You can see also three boards side-by-side in the photo below along with the Amnos LinkE CH32Vxx debugger & programmer board.