I would agree that this cost-plus pricing structure applies in some cases. Some companies definitely want to constrain the universe of SSO users. But this will

I would agree that this cost-plus pricing structure applies in some cases. Some companies definitely want to constrain the universe of SSO users. But this will usually show up in pricing structures with SSO as a relatively inexpensive add-on feature -- not as part of an indivisible bundle. Seemingly we want to talk about both of these things as "the SSO tax" but I think we can agree that they're pretty different scenarios.