Some airplane manufacturers offer merchandise such as airplane models at their official online stores. Suppose you wish to purchase an authentic Boeing airplane model. Go to the Boeing Store’s Website at boeingstore.com and click on “Models.” Select an airplane model and find its price. Do the same for two other models. Would the models you selected be considered as perfect substitutes or just substitutes? Why? Do you think there are other products available that would be considered substitute for the authentic models you looked up? Briefly explain.