I really only shop for food based on unit price, but sometimes there’s no consistency with the unit of measurement among different stores or even the same store!
Yup. Costco is usually pretty good about this, but I was buying something where they had $/oz and $/lb for a similar product, and other products have $/ea if they happen to be individually packaged. I still find I need to calculate it, which is really annoying.
I don’t know how Canada is, but I could see it being even more confusing if mixing metric and imperial units (e.g. for US imports).
So yeah, it’s incredibly annoying for those of us who care about cost per weight/volume instead of cost per package.