Pricing for complementary and substitute products simultaneously in the package-sale and separate-sale

In this paper, we present a model for the pricing of substitute and complementary products (four commodities) at the same time that the seller delivers the products individually, in form of package to the final customer, and compares the profits from the sale of each scenario and we have done a comparative study. In the package sale, two complementary products are delivered in one package that each of these packages is replaced by each other, but each item is sold separately in separate sales. The demand function for each product is a function of the price. To illustrate the validity of the model, numerical examples have been used and sensitivity analysis has been done on the important parameters of the problem.