The last-ever penny will be minted today in Philadelphia

I'm a little worried this will encourage vendors to increases prices up to the next 5 cent mark, which will cause inflation that we really don't need more of right now.

In Canada, most prices still end in 99. You still pay to the cent if you're paying with a debit or credit card, which the vast majority of customers are these days.

Gas stations price to the tenth of a penny per gallon. There is no 1/10 cent coin. Works fine.

This has not been an issue in Canada. There is sales tax, which basically randomizes the last digit.

That's because the law requires them to charge that extra 9/10. It's silly.

It doesn’t require it. There may still be (I dunno) fixed per-gallon taxes in the tenth-penny-per-gallon range, but stations aren’t forced to handle it the way they do.