Nominal cost here has the meaning "(of a price, consideration, etc.) named as a mere matter of form, being trifling in comparison with the actual value; minimal. " In this example, $1 is termed as the nominal cost because it is very less in comparison to the actual cost ($200). Hence by giving tickets at nominal cost, the airline is promoting itself !

nominal cost is the is the money cost of production.it is also called expenses of production.these expenses are important from the vier of the producer. he must make sure that the price of the product,in the long run,covers this expenses including normal profit,other wise he cannot afford to carry in the business.

A nominal cost is a minimal, or low cost. It would refer here to $1.