The best person to talk to in a store is the stock person. I was in a small market today and reached to get a small container of milk. The stock boy said, this one is a better buy, it’s on sale – save money. I put the smaller container back and got the larger one. The difference in price was only 26 cents but the difference in size was quadruple. I have never frozen milk, but it is possible to freeze it for later use.
Cashiers are often ones to ask about sales but to actually find items on the shelves and whether or not things are in stock… ask the stock person.