Regarding the shared belief of Marx and Rand that self-realization is achieved through work, neither can be credited with any originality. The source for this idea is Hegel, specifically his analysis of the master/servant dialectic in The Phenomenology of Spirit. The connection is most obvious in the case of Marx, who was a second-generation (Left) Hegelian, like most German philosphers of his generation (Schopenhauer had a few disciples at the time, but not many). In Rand's case, her claim to be an Aristotelian can obscure the connection, but Hegel had a huge influence on Russian thought.

This idea--that self-realization is achieved through work--is initially in tension with two other ideas in German thought: that self-realization is found primarily through thought (Kant), and that it is found through play i.e. art (Schelling). Hegel incorporates all three ideas through his use of dialectic (whether he does so successfully is open to controversy). Marx certainly gives priority to work, as he must given his commitment to materialism.