Guys. Read Marx.
Marxist economics is a critique of capitalist political economy. It is NOT a description of economic rules that is valid under every system. Marxist economics describes capitalism, perioid. Das Kapital contains no information WHATSOEVER that would be useful for socialist economics; that is one of the huge mistakes that socialist states have made in the past. The labor theory of value applies to capitalism. There is no value under socialism. There are no commodities under (developed) socialism; at the very least, there is no commodity production in the sphere of production (i.e. no selling of labor power because labor power has ceased to be a commodity).
Look what Marx says in the very beginning of Capital, Vol. II:
True, in the act M — L the owner of money and the owner of labour-power enter only into the relation of buyer and seller, confront one another only as money-owner and commodity-owner. In this respect they enter merely into a money-relation. Yet at the same time the buyer appears also from the outset in the capacity of an owner of means of production, which are the material conditions for the productive expenditure of labour-power by its owner. In other words, these means of production are in opposition to the owner of the labour-power, being property of another. On the other hand the seller of labour faces its buyer as labour-power of another which must be made to do his bidding, must be integrated into his capital, in order that it may really become productive capital. The class relation between capitalist and wage-laborer therefore exists, is presupposed from the moment the two face each other in the act M — L (L — M on the part of the laborer). It is a purchase and sale, a money-relation, but a purchase and sale in which the buyer is assumed to be a capitalist and the seller a wage-laborer. And this relation arises out of the fact that the conditions required for the realisation of labour-power, viz., means of subsistence and means of production, are separated from the owner of labour-power, being the property of another.
In a sentence: Exploitation and the sale of labor power are inseparable from each other. The end of exploitation ends the "commodity-ness" (commoditification?) of labor power and of all other goods, too. Without a market (and there is no market under socialism) it's superfluous to speak of commodities, anyway.
As to the Juche concept of a proletarian I am left with half-agreement half-disagreement. On the one hand they are 'Spiritually Proletarian' in that by fighting for liberation they are fighting for us. But they can still be bourgeoisie though if they still privately own a segment of the means of production and have not turned them over to the organization. I guess you could say I agree with the concept so long as the economic angle is not forgotten.
Ulrike Meinhof (of the Red Army Faction) addresses this. In one of her last texts, she defends her comrade-in-arms, Andreas Baader, from bourgeois accusations that he, as a "non-proletarian" can't be a guerilla fighter anyways.
Wunder's stupid thought, that Andreas supposedly never worked in a factory [...] is wrong. Andreas has learned and understood, in the factory, on the streets, in prison. It shows how psychological warfare tends to portray the RAF as a bunch of guys and girls from the upper middle class who were socialized bourgeois. If you really want to talk about sociology, it should be said that half of us do have a proletarian background - school, factory, nursing home, prison. This assertion [...] tries to negate the fact that all fighters of the RAF have learned and worked in the grass roots projects of the New Left since Easter of 1968. The fight itself proletarizes the fighters. This - freedom of property (she's talking about the fact that fighters typically don't own anything, just like any proletarian.) - is the understanding of the Korean party about the proletarian relation to the fight for communism: the Juche characterization of the proletariat as the antagonist of imperialism, this means, as the subject of liberation. This certainly isn't a sociological definition of the proletariat. But we're not interested in that. "Proletariat" is not a concept from the fascists' theory of descent - it describes a relation. The relation of the guerilla to the people describes the relation of the proletariat to the imperialist state, defined as deadly hostility, as antagonism, as class war. "Proletariat" is a fighting word.
She then goes on to quote Sartre:
It is true that the proletariat carries within itself the death of the bourgeoisie; it is true that the capitalist system is being destroyed by structural contradictions, but this does not necessarily imply the existence of a class consciousness or a class struggle. In order for there to be consciousness and struggle, somebody has to fight.
She goes on to explain:
But where does Wunder's assumption come from? Does he mean "Arbeit macht frei" (Labour will set you free - which was written above the entrance to Auschwitz) - that is, the concentration camp? Or does he mean the protestant work ethic, that is, quote, "labor as the source of all wealth and culture", an attitude from the Gotha Programme, with which [the social democrats] couldn't achieve anything during the big unemployment of 1930, except to hand over their political power [...] to the fascists? On this - on the mystified concept of labour of the Gotha Programme - Marx only said, frankly, that "the human being who does not own anything but his labour power must in all societal and cultural circumstances be the slave of the other people who have made themselves the owners of the concrete conditions of labour", from which Marx deduces the economical necessity and the political right of the workers to leave the factory, arm themselves and fight the state. And only for this we refer to Marx, because he scientifically justified the necessity of insurrection and the class struggle as class WAR against the parasitical network of repressive and ideological apparatuses, against the bourgeois state. All this babble is just cynical as there are more than 4 percent, respectively over a million unemployed in the Federal Republic and almost 5 million in Western Europe.
When the workers have left the factory, they surely aren't proletarians anymore from a socio-economical point of view. But it is a necessity for them to leave the factory, and with it, their socio-economical proletarian credentials, behind, to become revolutionaries, or subjects of liberation.