I just went ahead and read The Poverty of Philosophy by Marx (an answer to Proudhon's The Philosophy of Poverty) today and oh boy that Proudhon guy is such a clown. His work is pure, unadulterated petty bourgeois idealism and circular thinking (and somehow his grasp of basic mathematics is even worse). And Marx doesn't spare his tongue; no wonder "their friendship finally ended" after the release of Marx's response (to quote marxists.org article on Proudhon).
Certified banger, Lenin level of dunk. Would read again.