I don't understand ebay either.
There are bargains to be had but I think, for sellers, the 'instinct' that silver coins are valuable, coupled with the desensitising of consumers to debt, frequently works in the seller's favour. Push a button, choose a card, get the reward in the mail quite quickly.
Ebay reminds me of that little flutter you get when you're gambling - as you watch the countdown and you want that special something. AND they keep reminding you on email that there are goodies waiting to be swept up.
I still look but the SS traders and some favourite coins shops give better prices, and more reliable service I think.