One of the problems with thinking of money as being intrinsically worthless is being able to explain the facts of an exchange. My first thought was that money derives its value from what it is exchanged from. If this were true then to value money, one would need to know the value of each of the things in the exchange. I would need to know the value of the thing I am exchanging for and the the thing I will exchange the money for latter. This makes money effectively not a measure. One is still left with the question of what is the number of shoes that is the value of a house.
Then I began to think of time as a measure. Time is truly a measure of motion, because it is first motion, but then taken abstractly in memory. If there was not something of motion in time then it could not be used to measure motion. As another example, a ruler must truly have some spatial dimensions in order to measure things with spatial dimensions.
Hence, it seems that in order to be a measure, the measure must in some way possess that which it seeks to measure. Hence, money as such must be something valuable. What is used as money seems to be arbitrary within certain constraints, e.g. sea shell, chickens, gold, fiat dollars, etc. However, whatever it is must be something that is actually valuable that can be used as a measure against which to judge other things value.
This seems related to time as well. For the choice of motion to use for measuring motion is arbitrary whether is be the motion of the earth around the sun, the moon around the earth, the mechanical ticking of a clock, the frequency of radiation from an isotope or something else. A good measure of motion is something stable and regular in its motion so that the irregular can be measured by the regular.
A good thing used for money ought to have certain properties such as durability and difficulty to counterfeit, etc.
Even so, the difficulty still seems to remain as to the question of how much money, whatever it may be, is a pair of shoes and how much money is a house worth. However, this may be determined, there is a least one measure against which shoes and houses and all sorts of property may be measured.