ACT ONE: MEATY YUM
ANSWER: For each topping - $1.5 for the regular cheese pizza - $10
Question 3: No, the website just specifies how much the toppings are, and not if you double the amount if topping. It is saying you have to pay for the kind of toppings not the amount.
ACT TWO: PIZZA TRACKER
The equation for this question is because in all of the four pizzas they all have at least one topping. The pepperoni is cheapest and the pizza without the philly steak is the most expensive since it is a large and has the most toppings. The lowest base price would be 7.99 because the pepperoni is the cheapest and has the least expensive topping and if you would remove it, you would deduct $2 dollars away because the price of the topping.
In the graph, you can see people would rather get a big pizza with less toppings than a small pizza than lots of toppings.