From WebProNews
Since justifying an eBay store for those with manageable inventory is fairly simple, and considering the SERP benefits, there are some business-related things that need to be considered when launching one. The first to be concerned with is the amount of fraud that can take place on eBay. Since the auction site started, it has always fought against non-payment, identity theft, and a litany of other complaints.
The second con is that the costs can be pretty steep, depending upon how many items you want to sell. The costs per month can range anywhere from $9.95 for 5 basic pages, $49.95 for 10 featured pages, and $499.95 for 15 anchored pages.
The third con depends on your product – is it easily shippable? Not all businesses will be sucessful on eBay.