Marx's purpose of theory of value is to give workers justification

What you are calling the domestic economy is where the labor power commodity is reproduced - off of work.

Remember : labor power as a commodity is one of the defining characteristics of capitalism ; wage-labor sells its labor power , the only commodity it owns ; doubly free labor; wage-slavery.

And labor power is the only factor in production that can add more value to a commodity than the value that went into making it . Non-human forces and means of production can only add as much value as went into them .

This is a sort of humanist , mind over matter , aspect to Marx's theory . Human laborers can will themselves to work extra. Machines can't. It's a difference between subjects and objects in the Hegelian terminology .

You're talking about operationalizing Marx's theory of value to think of reforms of capitalism . That's a misuse of Capital and theory of value. It's not to use value to make better predictions of the prices in the market , or predict the business cycle or reform the business cycle ; or really even to find more wages to pay workers , although it not adverse to being used for that of course. The main purpose of the theory of value is to give the working class an deep, scientific , philosophical , justification to expropriate the expropriators , including abolishing the price system , contra Hayek .