You assume that other people can simply bring bottled water to market & compete with discoverability and access to customers with established players?
Or is your point that all people in a market with leaded water should be paying $100 for pure water because it is inherently worth that much per the market.
No, I assume that if anyone can bring bottled water to market, they should have a strong incentive to do so whenever there is a strong need for more of it.
But they (everybody) can't. Bringing bottled water to market requires a clean source, rights to acquire it, and a manufacture & distribution network. Plus retailers. As well, these things are often blocked to newcomers because of existing deals with big players.