Regarding Doba, unless you plan to sell 100's to 1000's of items (Remember I said Sell, not just listing them on ebay) you will not really make profit after fees etc, Esp on EBay.
Remember that so many people are using Doba, esp on ebay, that the selling price on places like EBay are dropping so much that Ebay itself is turning into a Wholesale Provider.
I was with doba for about 15 days. It was 15 days too many. By the time you fid somethign worth selling, they are out of stock b/c someone found it first.
They are a legit company and offer a great service (DropShipping) however if you are an Ebayer, I would not bother.
If, on the other hand, you are looking to stock a physical store, it might not be that bad.