Dear professor Wolff, I was watching your second session of introductory course to Marxian economics on YouTube when a question came to my mind. Merchants and money-lenders enter the market with money and leave it with more money. What they do for gaining more money is to buy the commodities at the price of their value and sell them at a price higher than their value, which is certainly unfair. Now in Marxian economics we argue that the industrial-capitalist pays the workers less than what they added to the value of the tools and raw materials he has bought, but there is another possibility; he might pay the workers a wage equivalent to their labor, but sell their product at a higher price than its value. In this situation it is the consumers that are ripped off, not the workers. Is my described situation possible? If so, how can we distinguish between the consumer-exploitation (profiteering), worker-exploitation and hybrid case where there are elements of both kinds of ripping off present in the activity of the capitalist?