Some publishers such as Elsevier or Springer multiply the base cost of the ebook. On LibCentral the price shown is not what we end up getting charged for in these cases. Could you calculate the actual cost of the ebook at the point of ordering? That way we can assess whether we want to purchase the ebook at that price or not. For example, we recently purchased one ebook for $57.51 but when the email confirmation came it was for $115.02 as Elsevier charges twice in that case.