Things are still either wrong, or misleading. Behavior of the vault seems to bear out the assertion (above) the feature is for paying members only.
When I click on the Vault I see "You account has a trial subscription to our Lush Bronze, due to expire on 08 Jan 2016."
Further down, on the list of features, I see Premium Story Library Access (which I interpret as the Vault) with a checkmark in the Bronze column. What I was hoping to do was check out the vault to see if it is worthwhile (for me) to go paid.
I appreciate your further clarification
fw