Yes, the STM32F103C8T6 boards ("blue pill", "black pill") are another very low cost (<$3) alternative and it looks like the market is being flooded with them. It will require someone more experienced to evaluate the possibility of a Nano upgrade and just how well the Arduino IDE works with these STM parts. I guess you can get them with 32KB or 128KB of program Flash and 20K of RAM.
73 Kees K5BCQ
