I also just acquired a 2014 MacBook Air for two packs of coffee to use as a distraction free tty writerdeck and toy around with, as it's my first piece of Apple hardware.
What's wrong with them? The M1 was popular and now people selling them are competing against a lot of other people selling them which suppresses the price. Like it or not, Macs are mainstream and therefore aren't going hold a "magic" high price.