She passed $4 to him. The boy asked how much does it costs and she told him it's $2.70.
The boy reached the stall and saw a tray of chicken breast meat placed prominently on the front of the fridge with the price tag.
He placed his order with the helper.
The helper packed and handed over the meat, collected the money from the boy and returned him the change.
The boy looked at the change and realized its only 80 cents instead of $1.30.
He told the helper about the wrong change.
The helper replied him the one he bought costs $3.20 instead of $2.70 as it's bigger and pointed to another tray inside where the bigger chicken breast meats are supposed to be . The boy didn't know about the bigger ones as he always see his mom paid $2.70 in the past when he followed her to market and thought there's only one size. And he only saw the ones priced at $2.70 in the fridge.
Since there are two sizes available that the boy didn't know, why didn't the helper ask the boy which one he wanted? Why do you think the helper sold the bigger one to the boy? Is it because the helper saw he's a boy and so thought he will has a bigger appetite?
Did he see this as an opportunity to sell the higher priced one to an ignorant person? Or the bigger one is more value for money for customers (owner makes lower profit margin)?
What if the boy is asked to come back and change to the smaller one?
If you were in the boy's shoe, how will you feel about this stall selling a more expensive priced item to you without asking you first?