There is no such thing as "society", just individuals. There is no absolute value, only relative value placed on it by individuals. Price is nothing more than the least value placed on item by everyone who holds the item compared to the least value placed on another item by everyone who holds that item. In other words, price is an emergent property from the "LACK OF TRADE".
Purpose and Utility are both PERCEPTIONS that are unique to every individual. Hence, they are not a property of the item but of a person's judgement. Purpose and utility can cause people to perceive value, but they are clearly part of the perception and not the item.
I think we're talking about the same thing, if its Mises definition of value, although I would probe your use of it. I may not be well versed in Austrian economics as I'd like. But I'm here to learn. Just to refine what I said before: Value is subjective to each individual and is determined by that individuals belief that it will help them achieve a certain desire/goal/satisfaction. The purpose of that person and the function and usefulness of that object are needed in this definition.
To say purpose and utility are solely perceptions and not inherent in any item is a definition is that falls upon itself. Let's look at your quote again. "Purpose and Utility are both PERCEPTIONS that are unique to every individual. Hence, they are not a property of the item but of a person's judgement. Purpose and utility .... they are clearly part of the perception and not the item."
That's like saying properties of a object is solely a mind experience. The raw material (your brain) in which you use to make these analytical judgements and evaluations, is in of it itself not useful? If the brain that's forming these perception, has no inherent function, purpose, or usefulness whatsoever; then where does this experience come? Where does the judging (the function/purpose) come from if its not a property of brain? Then what's the purpose of the brain existing in the first place, if its purpose and utility is not to judge?
Uniform objects can have inherent properties that describe its function and usefulness. The difference is within the definition of value. Value differs from individual to individual. Value of utility differs from person to person. Utility and function itself does not differ from people to people because they are distinct elements of the item. However, individuals discover for themselves and by observation of others, what they think the known usefulness and function of an item/material is to them. This is what they call value.
If also we're saying all value and metrics is relative, and nomenclature does not matter, and rather its random what you and other individuals make out of it, like Bitrose, Bitappl, Bitgorilla, then should we not correct a child when they call a Airplane a duck, or a sofa a truck? Most parents would correct their child saying that its a plane and a sofa that they are pointing at because of its appearance, design, and function. Its simply not that thing. Its something else. I respectfully bring this up, as a reminder for what we can learn from the original pegless BTS.
Economic value is relative, but it does give rise to objective value. If it hadn't how would we know that a company is performing profitability or not? Or how a country ranks against another country if GDP, an absolute metric can't be used?