Value of money
It is not entirely correct to treat money as if it has no intrinsic value.
The value of an object is exactly what someone is prepared to pay for it right now. Put another way, the value of an object is established by people wanting that object, the value is not intrinsic to the 'object'. A farmer may value a load of horse manure rather differently than the resident of a studio flat.
Items of money are in fact objects (if you wish to get even deeper in, refer to Why Aristotelean logic does not work). Money objects are indeed valued by humans, thus money does have a real value. For example, the person wishing to sell the horse manure will very like be inclined to take money in exchange for the load, although if offered a brand new shiny motor car or a large sparkly diamond may well like that price even more.
Money is constantly exchanged for other items, including money from other countries and other negotiable instruments. The international exchange rates give an idea of the current value or desirability placed upon various issues of money.
http://www.abelard.org/inflation.phpAs Iron Sharpens Iron, So one Man Sharpens Another.