Would you be open-minded enough to here an opposing viewpoint? 4 Arguments for intrinsic value (I don't even buy all 4, just ideas):
1)
Value is the ability of a person to satisfy his or her wants. While wants are subjective it still holds that there are ideal wants, ie what a person should want. When all people value a good as they should a price is reached as it would be in any other market situation and that value is the intrinsic value of the good. What it should be worth.
This heads straight for morality. However, upon finding morality we are still constrained by the human condition: The imperfect ability to ascertain, process, retain and act upon information.
If we had perfect morality, information and ability inside of a normalized market system (the hypothesis goes) we would be able to attain the ideal intrinsic value of a good. As evidence I submit that any economy with superior information, ability or morality results in superior economic performance.
2)
Value may be personally subjective but a market value is an objective phenomena in a free market because no person directly determines it. Over time market values approach a long-term equilibrium. That long-term equilibrium is determined entirely by objective economic law. In this sense it is objective.
3) Intrinsic value literally means what the thing itself is worth. While we say that a person's preference for something is subjective, we may also say that a person's opinion of the value of a thing is that person's appraisal of the good's intrinsic value.
4) Finally, are preferences ever really subjective or are they simply predetermined by complicated interactions of nature? In other words, does free will really exist? Personally I think it does but it is worth bringing up because many people who believe in "free markets" have no reason to think that free will really exists. If free will does not exist then all prices are non-subjective ie objective because even what we perceive as our own preference is really determined objectively.
Just food for thought. Let me know what you think.