Re: Water Prices
Haven't you missed something? I'm not entirely sure where you live, but in England where I'm staying, a 750ml bottle of water is regularly priced at similar, if not much higher prices than 1.5L bottles. The 500ml and 750ml bottles are sold at convenience, you buy it to accompany a snack, sole drink, or while on the go, and the 1.5L bottle is sold for greater supply. I see both price brackets you've posted for their respective capacities daily.
Of course water is water, and you don't have to conform to market sectors. However most do, and I can only see you comparing different markets rather than directly comparing prices cross-country.