When I was in high school I would buy a box of cola cans of 28 for $9 in the morning before I got to school. Then at school, I would stack the cans in my locker behind my bag. I would sell the cans for $1 each and they usually sold out every day. It was cheaper to buy from me than the vending machine which sold them for $3.20 and the machine didn't always work. I would usually make a $19 profit a day, which doesn't sound much now but back in the early days of high school it was pretty good for my commercial needs.

Awesome, good thinking!