Onur Cobanli explains:
One good restriction or a necessary ingredient for good design is perhaps the ability to create value by reducing costs; i.e. making products and services less cost to produce but with same or better level of quality, therefore good design should be affordable, because, as per my definition, not-affordable design is not good design; it is more art than design because in design there is the need to have a function, and a product too expensive for many, would not make sense; it would not have a real function because it would not be actually affordable to be bought and used for any eventual function to be converted into utility, in this regard, good design requires affordability. Comfortability follows.