The phrase "extra charge" refers to an additional fee or cost that is imposed on top of the regular price for a product, service, or experience. It can be used in various contexts such as when purchasing something at a store, using certain facilities, participating in activities, or hiring services. The extra charge could be due to factors like premium quality, special features, additional services provided, or simply because the item is considered luxury or high-end. Essentially, it means that there will be an added expense beyond what was initially expected or anticipated.