Is our sub fee not enought

[Skivvy]

It is relevant as it is an example of how a business has a flat rate for standard services and charge for extra. This has been the business model for many businesses forever. It is the way of business, for good or ill.

The business model for at least two very well-known paid subscription games, including SE's only other MMO, was that all items were included for your subscription fee. You can't place every single product into a tidy little basket and expect them all to conform to the same business rules. Different products come with a different set of services and expectations from the consumer.