The url for the second passage ("what is wealth" etc.) is mistaken.
It should be:
<http://www.marxists.org/archive/marx/works/1857/grundrisse/ch09.htm>
As the 1881 draft of the letter to Vera Zasulich (<http://
www.marxists.org/archive/marx/works/1881/03/zasulich1.htm>)
demonstrates, Marx didn't require capitalist conditions as a
necessary feature of the context from which the penultimate social
form could emerge. He did require, however, the developed forces of
production created by capitalism outside this context. He also
required that the conditions (in the case of Russia, those of the
peasant commune) be consistent with the development of an
"individuality" with the developed capabilities required to imagine
this penultimate form and then build it by "appropriating" (in the
sense specified in the passage from the German Ideology) the forces
of production developed elsewhere.
This doesn't describe what happened in the Russian and Chinese
revolutions, i.e. those revolutions were not self-organized
individuals appropriating forces of production developed elsewhere
and using them to create productive arrangements from which all
barriers to full human development were removed. Moreover, the
revolutionary transformation Marx has in mind couldn't have occurred
in those contexts because (contrary to what he assumes about
"individuality" in the Russian peasant commune) the actual
"subjectivity" characteristic of them lacked the developed
capabilities it required (a fact revealied by, among other things,
the religious beliefs characteristic of the commune).
What's missing from Zizek's interpretation of Marx is Marx's idea of
the historical process as a set of internally related stages in "the
development of the human mind." Religious beliefs are, like forces
of production, treated as an index of this development.
“The most rigid form of the opposition between the Jew and the
Christian is the religious opposition. How is an opposition
resolved? By making it impossible. How is religious opposition
made impossible? By abolishing religion. As soon as Jew and
Christian recognize that their respective religions are no more than
different stages in the development of the human mind, different
snake skins cast off by history, and that man is the snake who
sloughed them, the relation of Jew and Christian is no longer
religious but is only a critical, scientific, and human relation.
Science, then, constitutes their unity. But, contradictions in
science are resolved by science itself.”
<http://www.marxists.org/archive/marx/works/1844/jewish-question/>
For instance, "Christian" beliefs that make the eternal suffering of
one's "enemies" at the hands of a vengeful sadistic "god" a source of
"rapturous" joy indicate a degree of development required for the
creation of the penultimate social form. This is confirmed by a
psychoanalytic understanding of such beliefs.
Ted