Yes, these are all authentic, if the pictures are of the actual bag (and that is always an if). A lot of sellers are leaving eBay, and looking for another marketplace... one where the fees are not so high, and the seller has some protection, as well as decent traffic. eCrater has been suggested:
http://forum.purseblog.com/ebay-forum/i-love-ecrater-com-298337.html
If you do use this marketplace as a buyer, I would suggest that you scrutinize the seller feedback as you should on eBay, and pay via Paypal where you have buyer protection, and better yet, use a credit card just in case things do not go well. You are breaking new ground, but competition will be good for eBay. Let us know how it goes!