[Wowfunhappy]

Paying by cash has an opportunity cost too, over the course of doing it many times.

I think the bigger problem is that if your bank balance is (consistently) below a certain threshold, most banks will charge you a monthly fee.

[monocasa]

Before cashless stores, what was the opportunity cost of paying by cash?

[Wowfunhappy]

You have to spend time getting cash out of your wallet and counting your change. The time adds up.

[monocasa]

You also have to spend time putting in our card, then your pin, then signing something, all the while waiting on their slow connection on each step. IMO, it's faster to use cash in most cases.