It's rarely purely price/oz. Often it's mixed units - eg for granola bars or similar you'll see four different items listed at - Price/oz Price/lb Price/bar

It's rarely purely price/oz. Often it's mixed units - eg for granola bars or similar you'll see four different items listed at - Price/oz Price/lb Price/bar Price/unit (which might be bar or package of two bars) So you get tk calculate the difference in your head.