more expensive than a gallon of gas..?
 

interesting:

http://cockeyed.com/science/gallon/liquid.html

My problem with these sorts of comparisons is always that they aren't comparing apples to oranges. A lot of the cost of liquid products purchased at the store is the container it's in and the cashier having to ring each one up (thus higher cost for the retail outlet).

Ever buy water multiple gallons at a time? It's 10c or less/gallon in quantities like a tank of gas.