You are learning quantities: you will read the scene it happens in, take apart the pattern behind them (quantity vocabulary), hear them in a conversation, rehearse them, and finish by saying one thing out loud to be graded.
American markets use pounds and ounces, not kilograms. A pound is about 450g. One "pound" of anything at a NYC market costs $3–$18 depending on the product. Three phrases handle all quantity transactions.
Chelsea Market is a 900-foot-long food hall built inside the former Nabisco factory on 15th Street — where Oreo cookies were invented. Now it houses specialty food vendors, restaurants, and one of the best cheese shops in New York: the Murray's Cheese counter.
Murray's has been in the West Village since 1940. Their Chelsea Market counter has 300+ cheeses, all available for tasting before purchase. A cheesemonger in a white apron is explaining the difference between two Vermont cheddars.
The stranger interrupts politely. "Excuse me — could I try that one?" He points at an aged Manchego. "How much is it per pound?"
"Eighteen dollars a pound. It's from Spain — La Mancha."
He tastes it. "I'll take half a pound, please. Could I also try the Vermont cheddar?"