Automobiles and refrigerators are considered to be items sold as optional product pricing, what other products fit into this category?
Nowadays, perhaps the most prominent example of this sort of pricing can be seen in the airline industry.
Optional product pricing occurs when a main product is sold along with some accessories. The main product can be sold at a relatively low base price, but the firm can still get higher profits by selling expensive options to go with the basic product.
The airline industry today does this a great deal. There is the basic product, the flight. Passengers can then buy other products as add-ons to the basic product. For example, passengers can pay to check a bag or bags. They can pay for snacks. They can pay to reserve an aisle seat or a window seat. All of these are options that are tacked on to the basic product that is being sold.