The only time I've seen "too cheap to meter" actually happen was the city water in Chicago, and even they are adding or have added meters now even though they have effectively infinite fresh water from Lake Michigan.
Cheap raw materials does not affect the cost of everything else that must be done to prepare and deliver the product to the end user.
> they have effectively infinite fresh water from Lake Michigan.
While the total volume of the great lakes is appropriately great, the areal recharge rate is much lower than one might expect. IIRC about half of its recharge is from groundwater, and so competes with aquifer withdrawals elsewhere.
Cheap raw materials does not affect the cost of everything else that must be done to prepare and deliver the product to the end user.