What is the average salary of a Taco Bell franchise owner?

In the US, it would be somewhere between 27 and 37 percent of the cost of the item.

Certainly some beverages are a lower cost percentage and there are some specialty items in more expensive places that are slightly higher in cost.

Of course there are many other costs in a restaurant (to the owner) and if a restaurant makes more than 5% profit after all expenses - it is a great business.

There are also great disparities in costs in some fast-food/convenient-food restaurants. In most Burger chains, if customers only bought the burgers they would have to greatly increase the price of the sandwich or go out of business. But french fries and drinks are much more profitable.