What's funny is watching someone buy a case of dollar-a-pint bottled water when the same R/O filtered water can be had in generic jugs just down the aisle for under buck a gallon.
$0.86/gallon for distilled, usually. I use it in my radiator[1], iron and suit steamer[2] to minimize scale from the local tap water. When you can find it in the 2.5 gallon jugs, it's sometimes an even better deal.
[1] Just under 2 gallon system capacity, so a gallon of antifreeze and top off with one jug of water a lot cheaper than two gallons of premixed coolant, then I save the af jug, buy another jug of each later, and make two gallons of premix myself for topping off.
[2] Maybe two gallons a year between the two. Hardly a major expense, and cheaper than having to clean them out with vinegar every few months.