I think there's a slight difference between your concept of "subjective value" and my concept of "context-dependent objective value," but correct me if I'm wrong.
My version of this concept preserves the ability for a person to be more or less correct in their evaluations, whereas yours doesn't.
In my conceptualization, there's the thing I'm valuing, how much I consciously value it, and then there's it's actual, objective value relative to me. These last two are separate.
The reason I think it's necessary to keep these separate is because...
For example:
I could value ice cream, and I could buy it to eat it, but that doesn't mean that it was a good thing that I bought and ate that ice cream (even for me).
After all, Ice cream is generally not good for me. There are exceptions, but there really is truth to the statement "I shouldn't eat ice cream three times a day, even if I go ahead and do so."
If I did this, I'd be expressing incorrect value to the market. The market would begin overproducing ice cream because of my increased demand, and this wouldn't be a good thing.
Does this mean that I think government should step in and regulate ice cream out of existence? No, it doesn't. It just means that the market is only as good as it's participants at approximating value. It just happens to be the best means we have of doing so.