Cost per guest for child

When you invite a child to a party you should pay for their food and entertainment. Your guests should not be expected to pay or you are not the host of the party. If guests each pay their own way then it is a "gathering" not a "hosted party".

You can note that "Pizza, drinks and 5 tokens (or tickets) included". Therefore, if they want to purchase more than 5 tokens they need to bring extra money themselves.