Optional Product Pricing

The price of optional and accessory products along with a main product. For example airlines will charge for optional extras such as guaranteeing a window seat or reserving a row of seats next to each other.

There is another example. The Pizza’s restaurants also have optinal product pricing. They charge extra money for extra topping depending upon the material such as chicken, cheese, vegetables, sausages etc.

Reference:
http://www.marketingteacher.com/Lessons/lesson_pricing.htm