What is expensive is paying the typesetters to place the movable type in various places, and to create plates with the various graphics. Oh wait, we don't need to do that anymore.
At this point, there is no rational justification for what Elsevier is doing now except greed. They actually have some other services that makes sense, but this lock on academic papers is simply a historical accident that is no longer relevant.
I do know that reviewing is free (I have done it).