For years now you will find that everyone you look at on an auction is anonymous. However, you can read your own handle. Of course, eBay knows who is bidding. And they keep track of this and a seller would be in big trouble in short order.

When on eBay click on Customer Support at the top and it will give you all the requirements, etc. as to how it works. There are many fees which a seller must pay. All taken into account by the seller.