It all depends on what you are selling. If you are listing that many items and resisting them then you might want to look at a ebay store. Here is the Link http://pages.ebay.com/storefronts/subscriptions.html
It is a monthly fee $15.95 a month but your insertion fees are .03.
Most people are buying right and living on lots of sales per day not how much you make on selling 1 or 3 a day. I don't make a lot on my $10.00 sales but if they then buy a $50.00 item or come back later then the small sale pays off. Most people are using eBay as another route to supplement there Brick and Morter store.
I look at me eBay fees (and no one is happy with them) as the same expense as a real store. In other words if you are working on a 40% markup then after all your fees you should make the same amount as if you subtracted what your expenses would be in a B&M store.
This is why we are here at AucComm trying to get our own stores going, so we can get away from eBay.