If you ask someone about the cost of a product, either hardware or software, you typically get an answer in dollars. HBO, for example, is $15 a month, and Facebook is free. The reality, however, is a bit more complicated.
All products—virtual or physical—have financial costs and cognitive costs, both upfront and on an ongoing basis. The financial costs are easy enough to think about. You might pay upfront for something or via an ongoing subscription. Financial costs are easy to compare and almost all products are priced equally for all of their users.