I don’t know anyone who says “I need (x of weight) worth of peanut butter!” And then uses the weight as the measurement.
This isnt what that price is for.
Say I’m buying ketchup. Bottle A is 725ml and costs $5. Bottle B is 967ml and costs $6. Giving you the cost / mL tells you which one is actually cheaper, not which one costs less.
Everyone I know says “I need peanut butter. Oh, $6.97 is less than $8.27” and never checks the weight.
If this truly is the case, be happy that nobody you know is struggling to pay for groceries 😉
You just absolutely demolished so many a man’s ego