What I want to tell is that you can buy a 24 pack of 16.9 oz bottles of Aquafina water from Peapod (when you tell them you live in Newton) for $5.99. 16.9 oz is an odd amount, unless you happen to know it is really half a litre, a much more understandable unit. This means you are paying just about 50c per litre. Aquafina is a "middle of the road" brand of water which is basically filtered tap water from some municipal system somewhere.
Compare that to the current pricing for tap water here in Newton, available from the City Water Department. If I am a profligate user of water, then I would pay the top rate, including the sewer fee, of $13.42 per hcf (for using more than 70 hcf per billing cycle or year or whatever). What is an "hcf"? It is a unit of one hundred cubic feet, which happens to be a little over 2831 litres.
You can do the math... but, what the heck, I'll help you... that works out to be less than half a penny per litre, and so:
Now that's the real cost of bottled water!
Bottled water costs over 100 times what you pay for water from your tap (at least in Newton).