And a couple of water jugs to keep in the fridge, we have two of those, plus the kids have two re useable water bottles each, that they take to school or when ever we go out somewhere, missus has her own and so do I, no one touches anyone else water, and each person is responsible for their own water bottles etc.
So if you don't fill them up you go thirsty or you drink warm water from the tap
Worked it out once (cost of bottled water) for a work mate who was always short of cash.
He bought 2-3 bottles of water a day, and his missus did the same, and I worked it out on a conservative $3.50 per bottle.
So that is between the two of them $21 per day or $147 per week, or $588 per month, which works out to be about $7000 per year before they bough anything else....thats a nice holiday with the family, a good second hand car or motor bike, or your car rego, insurance, and xmas presents all payed for with change left over......adds up real fast.