not sure if I'm following you, but......
I live in water metered house. paid about £40 per month. on plus side have nice green grass from the waste water! I use about 600 to 700 pure per week, so that would be bout 1500 litres per week in including waste water.
you can get separate commercial metre added, but you have to pay to get it installed (possibly depending on area, I'm Welsh water), and apparently cost water per litre is more too? still viable being on metre, especially if have decent pressure, but better if not metered obviously!