The link that is located directly beneath the "Choose Item Specifics" link on the Auctiva liter page is the "Custom Item Specifics" link. I reviewed the first couple saved listings in your account and this link was present in each of them, so hopefully you are now able to see this link to.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .