[Coda]

No, on the contrary, an economy in this context means something that IS cost-efficient -- things like discounts for buying in bulk ("economy-size").

What that statement is saying is that being a monopoly made money for the company by reducing operating costs, but monopoly companies could also make money by controlling how much they charged for things, because customers couldn't just go to a competitor for a better deal.

In your defense, that's a REALLY poorly written sentence.