Omg that link is so incredibly econ brained. It's like bourg academic economists have to write garbage like this to prove they haven't read Marx.

Marx's formulation of LTV is explicitly that what is contained in value isn't labor, it is labor power. It isn't just work, it is working for the capitalist. Power is energy exerted over time, allowing us to determine the actual material composition of value which eludes the bourgeois economist and their idealistic and transparently useless equilibrium pricing. Marx teaches while bourg economics obfuscates. He is explicit and repetitive, which makes us truly consider the "stuff" of value. This is why liberals can't tell the difference between mercantilism and capitalism. Value is our time and energy, our limited renewable life taken out of us, much of which is unpaid, and converted into commodities which converts to profits for the capitalist. Private property has never been anything but a grift, a way to trick the masses into voluntarily surrendering our material bodies for a dream sold to us by parasites.

Capitalism is class oppression, if it wasn't it wouldn't create value, it would just shift it around like medieval mercantilism. Honestly I think this is where a lot of progressive liberal "Marxists" end up in an overly economistic interpretation, especially class reductionist tendencies. Misreadings of Marx lead to bourgeois economic obfuscation; a close reading of Capital gives us the basic formulations for dispensing with bourgeois economics for good.

"Jacob doubts whether gold has ever been paid for at its full value. This applies still more to diamonds. According to Eschwege, the total produce of the Brazilian diamond mines for the eighty years, ending in 1823, had not realised the price of one-and-a-half years’ average produce of the sugar and coffee plantations of the same country, although the diamonds cost much more labour, and therefore represented more value. With richer mines, the same quantity of labour would embody itself in more diamonds, and their value would fall. If we could succeed at a small expenditure of labour, in converting carbon into diamonds, their value might fall below that of bricks."

The other key thing to note is that commodities are not valued around the individual circumstances of their creation. So if I decide to make a perfect copy of a ‘bic biro’ pen, without the aid of specialist tooling and experience, it would take me hundreds of hours to make a biro, but the socially necessary labour for making a bic is the mere seconds of labour that a biro takes on the bic production line. The individual circumstance of the creation of my hand made biro doesn’t affect the value of the commodity.