alt Hacker NewsDynamic pricing based on personal data is not even a market, let alone a perfectly competitive one. Temporal dynamic pricing can mean almost anything, so might be ok (early bird lunch deal) or pure evil (bottled water now costs $100 because there is lead in the tap water).
Your evil case is not evil
The point of pricing water to that level is that it would induce other people who have access to bottled water to bring it to that market, as is desirable