There is too much competition on ebay now, everyone and their brother is doing it. Then you have these computer companies that build them and have access to wholesale prices, prices that you and I can only dream about, then they sell them for dirt cheap. Browse around on ebay sometime for custom computers, you'll see what I mean.
Ebay used to be a good way for someone to make money, nowadays if you want to make money on ebay, you have to be selling something unique. And there are websites dedicated to starting ebay businesses, and websites that dropship items that you can sell on ebay. You use their description of the item, their pictures, and you set up the auction and everything then when you sell, you do the order through the website, give the buyers address and everything and they will ship it right to them, you don't even see the product. It's so easy that everyone is doing it and there is too much competition like I said.
If you want to make money online, ebay is not the option anymore.