the last time there was a shortage of pi hardware (before the 4) - target in the US had these "learn hardware!" boxes on clearance for a few bucks, with a Pi Zero (not sure which one, wifi only) and a cardboard case and a daughter board. I still have a couple of unopened boxes in a cabinet.

Unfortunately, i've lost about 2 pis a year to hardware failure since 2018, usually the SD card overheats and practically melts. I'm not sure why, humidity maybe, or bad SD cards.