Anker's Soundcore Liberty Air earbuds are a solid alternative to AirPods at $50 -- which is less than half the price of Apple's signature wireless headphones. You don't have to pay even close to that, however, that since the highly rated true wireless headphones are currently.
This the lowest these quality buds have dropped; we normally see them priced around. Although, if you prefer those.
It's worth noting that these are a former CNET top pick for budget AirPod alternative, but they're now more than two years old. There are newer, cheap options worth considering but it's not likely you'll find ones as cheap as these.
In his, David Carnoy explains how these 'buds "sound as good or better than AirPods" with "solid wireless performance, five hours of battery life and come with a compact charging case that delivers an extra three charges." The big difference is AirPods will run you at least $130, while these can be had for a cool $20 right now.
Even if you've got a pair of go-to headphones you love, it's handy to have a backup pair for emergencies that actually sound good, and this is about as inexpensive as you'll find.