So many different ways to look at things.
They could charge sellers a 15 cent fee per card sold
every time a card is sold, and only charge buyers 10 cents per card after the initial $3. There's the 25 cents per card they are charging to ship now. The sellers that won't like this are the same sellers with inventory that slows the process of getting the money making cards onto the site.
I have thousands and thousands of cards I could sell for 10 cents each, but I think it's a waste of time and money at the moment. What's the point in selling a card for 10 cents when it cost you at least that much to list it? Just give the darn things away without wasting everyone else's time.
That's why I don't do it. I have a few cards listed at 10 cents I think because I didn't realize they booked that low when I sent them in. It was an accident.