plenty of folks coast through mba programs learning only superficially, but that shouldn't taint the value of the information itself. i gained plenty of confidence in the areas of finance, marketing, accounting, operations, etc. that i didn't have before and which was directly applicable to being a product manager and startup founder.
i've read a bit of marx but mostly in digest form. das kapital and adam smith's wealth of nations are on my list of older, original works that i want to read in full. i'm sympathetic to the labor theory of value, which both explored in their works, but most modern economists seem to eschew and even fear.