We are used to attributing a monetary value to virtually all physical things, as in many everyday situations we are (potential) buyers or sellers.
With this comes an almost subconscious knowledge of the intrinsic value of things that surround us - even if we don´t know their exact monetary value, we can decide rather well, which of any two items is the more valuable to us.
Obviously, great businesses thrive on the exploitation of collective misconceptions - be it by putting an extra-shine on the surface of an ordinary ball-pen, by offering the "extra 20% for free" on shampoos and detergents or by promoting their 21% p.a.-credit-facility with "just 75c./day" ( or "
Smooth monthly instalments of reduced value" as seen recently in an ad by a Portuguese bank ;-)) .
Now think water and animal fat: little doubt that anyone of us not living in or close to a desert is prepared to pay a considerably higher price for the fat, or ask for one if we happen to have a kilo of fat and a litre of water to sell.
Now think of a mixed product, and apply our - collective ;-) - ability to create an average from two given numbers: for sure, the price of any such product should be within the range of the higher and the lower of the two, according to the composition-mix.
Now think of - or check it out in your local grocery-store - the composition and price-ranges of all low-fat-labelled dairy items: using as base the price for regular butter, the price for the water-component of the low-fat version is easily double that of Perrier Table Water - and without the bottle.
We have tried hard to find a home-made alternative to obtain the same benefit without the extra-cost, e.g. soaking the bread in water (it´s rather difficult to apply the room-temperature regular butter without obtaining a ball-shaped structure), even before putting it into the toaster (bad idea - even though the short-circuit was fortunately limited to that appliance...we could have bought lots of the premium version of low-fat-butter for the price of the new toaster :s).
So in the end, we just help ourselves to a glass of water - 200ml of water on an average serving-size of 25g of butter result in 225g ultra-super-low-fat butter, for the price of just 25g of regular butter (we use tab-water...).
