This is something I worked on with my own kids. Jake and Emma love having summer bake sales on our block selling cookies and brownies. They realized that making cookies or brownies were the same effort and the same cost, but they could charge more for brownies. So they stopped baking and selling cookies altogether -- and their profits soared. They made $1,000 one summer.
When I was a kid in Miami Beach, I sold grapefruit from a tree in my backyard to cars that drove by. When a friend saw how much I could make, she wished she had a fruit tree in her yard. I realized that my tree produced more fruit than I could sell alone, so I made a deal to sell her grapefruit at half price as long as she agreed not to undercut me on price to her customers. I sold during morning drive time on my block and she took afternoons on her block. Not only did I make more money this way, I also learned how to expand my business.
This is another opportunity for parents to help. Sit down at the dining room table and map out a plan, playing with the numbers to see what kind of scenario will not only make money right now, but will also plant the seeds of valuable lessons in business. It'll look great on college applications, too.