LOL - I was a kid which was willing to sell, for a steep profit, surplus candy that I had purchased for my own consumption. A couple of the kids parents even complained to my father, who forgot to tell me until I was about 30.
Worked out well for me - because I was willing to walk to the store, buy candy with my money, transport it and then resell it, I was able to get my candy at no cost. The lazy kids who wouldn’t walk to the store, but were willing to pay high prices could then elect to do so.
No real difference from adults.
I went to a Catholic grammar school in The Bronx. Every classroom had several boxes of different types of candy. Once a day, we would have a short break, and one or two of the children would walk around the classroom selling the candy for the nuns. Cost was 1 or 2 cents a piece. It was one way the nuns raised extra money. I wonder if they are burning in Hell for this now.