chabadgal,
There is nothign wrong with that. They didnt force anyone to buy it. You wouldnt complain if they were selling cases for $5 so why are you complaining if it is $42.
It’s not so simple. This is an emergency situation, and many people cannot simply access another source of water – either they are flooded out of their homes or their utility water is contaminated. And with massive power outages, currency becomes more limited to cash, making it harder for some to pay, even if they had credit or debit cards.
To take another tack, imagine if right before Sukkos, the stores selling esrogim in a town got together and decided to up the price to something ridiculous, effectively insuring that large numbers of people in the town would be unable to fulfill the mitzva of arba minim. Would there be “nothing wrong with that”?