What problem are you trying to solve? Yes you can get one for $10 instead of yubico's $20, but yubico's have been researched the most and importantly they are very reliable. Many people successfully abuse them and while you always should add a pair of them giving you a backup, it would be a pain if it would stop working.

I'm asking because I'm curious about use case where you think you need them (even a bunch), but you think they are too expensive compared to value which you are trying to protect.

Reliability would be a good enough reason to me even ignoring all security aspects.