When I googled the "ranch auction site" this site came up Link hidden: Login to view - When I visited the site I found 3 square icons on top - the river, the ranch and the bay - all 3 icons when clicked on will redirect you to a certain site -
*the river - Amazon.com
*the ranch - Bonanza.com
*the bay - eBay.com
So they may be referring to Bonanza.com in the eBay forums that you read.
Hope this helps. :)