This is a ridiculous question
A better, reasonable question would be: Why is it that we pay more of a tip based on the price of the food? Whether I go to Applebee's (
) and spend $50 or go somewhere expensive and pay $200, often times the waiter/waitress is doing the same amount of work. Why do we leave a $10 tip at Applebee's versus a $40 tip at the expensive restaurant? If I order a Filet Mignon instead of a salad, why must I tip the waitress more money because she carried out something more expensive than a salad?