The unit issue is in the EU. You can't sell everything by 100 g or 100 mL, so it is ultimately up to the seller. Another example of it is toilet paper, sometime

The unit issue is in the EU. You can't sell everything by 100 g or 100 mL, so it is ultimately up to the seller. Another example of it is toilet paper, sometimes given in money/square, sometimes given in money/length.