“Price of goods” vs “Prices of goods”

I was just asked, in referring to the sentence: “The price of goods in big cities is usually higher than in small cities,” if it’s okay to swap “price of goods” for “prices of goods.” I said that goods is a singular group, and prices would only be acceptable if you put a modifying adjective that breaks the singular group into multiple groups such as “the prices of various goods in big cities,” but now I’m starting to wonder if that’s correct.