If anyone is on the hunt for affordable microcontrollers in stock : ) Despite the component shortages, there's some extremely low-priced microcontrollers still available, if one is not so choosy on package style.
For instance, MSP430G2212 parts are just 59 pence currently. It's only got 2kbyte Flash memory and 256 bytes of RAM, but that's still useful for a lot of things. The development environment, CCS, is stable, and coding for it is quite nice (although as mentioned, the amount of Flash and RAM could be an issue depending on what you want to do with it). The DIP package is large, but not all circuits require being compact.
To program it, one very cheap option is to purchase a MSP-EXP430G2ET Launchpad board, and use that to program the chip, however that's out of stock. The board has a 20-pin DIP socket so it’s easy to plug in the chip, program it, and then insert the chip intoyour circuit.
Another option is to buy an MSP430 programmer. The programmer needs to support 2-wire JTAG, also known as Spy-Bi-Wire or SBW, or 4-wire JTAG. A ‘BSL’ programmer is often cheaper but won’t work for this chip. A suitable programmer is MSP-FET. The older model MSP-FET430UIF will also work, and there are low-cost clones of the MSP-FET430UIF on AliExpress, which claim to support SBW, but I have not tried them.