Hi slot-this,
No - unfortunately it is not possible to post items for sale in your Auctiva store without listing them on eBay. Since there is a link to your Auctiva store in the scrolling gallery in your eBay listings, it would violate eBay's "Links Policy" if items offered for sale outside of eBay were available there.
If you have any additional questions or concerns, please feel free to contact our customer support team using the web form on the following page of our site:
http://www.auctiva.com/help/requesthelp.aspx-Mike