If you could produce infinite quantities of Chateau-Petrus, it would be extremely cheap. But since it depends on being produced at a specific location, with a specific know-how, the quantities are limited. In this case, the amount of labour involved has little effect on the price of the wine.
Back on topic, "expensive" and "price" again add the concept of profit to the value produced. The only value of wine is enjoyment, so even Petrus wine has little more value than similar wines.
That increase in value is largely labor from learning the trade and long running slow maintenance. The only part that is scarce is the soil composition, something that could be recreated with a large amount of labor. Similarly, discovering that that area produced quality wine was labor intensive as well.
No - not at all.
Good wine can be 'more expensive' simply because it is better!
There's more willingness to pay, i.e. better demand curve!
Doesn't need to be less supply!
Point being: not all labour is equal, ergo, the idea of something being valued upon the 'amount of labour' put into it is really not useful.
I just don't believe the labour theory of value is a useful concept.
I don't think Marx provides any understanding of how the economy works - other than to hint strongly that prices are really a function of power - i.e. when one group has a monopoly on some critical thing, i.e. land or capital, then they can use that to leverage over another group, and then you have basically class struggle.
I mean, it's useful rhetoric, I'm not sure if it's useful theory.
Sorry if this missed the mark completely. Would love to learn.