A major problem with the mainstream framework of thinking is that people are presented as if a scale of preferences were hard-wired in their heads.
Regardless of anything else this scale remains the same all the time. Valuations however, do not exist by themselves regardless of the things to be valued. On this Rothbard wrote,
There can be no valuation without things to be valued.
Valuation is the outcome of the mind valuing things. It is a relation between the mind and things.
Purposeful action implies that people assess or evaluate various means at their disposal against their ends. An individual’s ends set the standard for human valuations and thus choices. By choosing a particular end an individual also sets a standard of evaluating various means.
For instance, if my end is to provide a good education for my child, then I will explore various educational institutions and will grade them in accordance with my information regarding the quality of education that these institutions are providing. Observe that the standard of grading these institutions is my end, which, in this case, is to provide my child with a good education. Or, for instance, if my intention is to buy a car, and there are all sorts of cars available in the market, then I have to specify to myself the specific ends that the car will help me achieve. I need to establish whether I plan to drive long distances or just a short distance from my home to the train station and then catch the train. My final end will dictate how I will evaluate various cars. Perhaps I will conclude that for a short distance, a second-hand car will do the trick.
Since an individual’s ends determine the valuations of means and thus his choices, it follows that the same good will be valued differently by an individual as a result of changes in his ends. At any point in time, people have an abundance of ends that they would like to achieve. What limits the attainment of various ends is the scarcity of means. Hence, once a larger variety of means become available, a greater number of ends — or goals — can be accommodated (i.e., people’s living standards will increase).
Another limitation on attaining various goals is the availability of suitable means. Thus to quell my thirst in the desert, I require water. If no one willing to sell water is nearby, any diamonds in my possession will be of no help in this regard.