I think this illustrates how important it is to be clear about what you mean by ‘value’. I do indeed mean that I need water to live, and not whisky. But it is abundant, and therefore I can get it really cheap.

What you say (like with the book) could be construed as an argument that I should be willing to pay much more for my water – not just that, but even that I actually *should* be paying more than fractions of pennies for a litre, to signal that value to me.

I think we would agree that this would serve no purpose, but (if so) it also makes the thesis that WTP == value a bit precarious.