Ebay now charges around 15% for a transaction. However, you can list it as a buy it now and if it's above $1000 you pay a flat $100. I think a lot of dealers (stores) are simply listing inventory to see if anyone bites. if no one bids they aren't out anything. IF someone does - BINGO.
Ebay got too greedy and has basically driven out private sales. If you check the completed ads you'll see lots of items are never sold.
Many sellers will put high prices and sit on gear until someone comes along and wants it NOW and is willing to pay the price. There is nothing inherently wrong with this, of course. But it does lead to many uncompleted 'buy it now'.
Any professional ebay seller of camera gear will be so-called 'top rated' or 'power seller' which means they get 20% off the fees, so that $100 becomes $80. It's not anywhere near 15%. This site will break down the fees for you.
There are still plenty of private sales on ebay. They haven't been driven out, there are just perhaps a smaller percentage of the overall offerings.
ebay is by far the largest market of used camera gear, that's where the buyers are, so thats where the sellers go. It's no wonder there are more dealers now.