So your my primary interface for pens, having someone curate what is out there and present that to the world is how many of us know and learn about these products. Maybe you could have a standard list of products and you keep selling those products till you find better ones? Most of us know that we can find these products other places, but that is just the thing, we don't even know what to look for. You do a great job of photographing the products, and explaining them. Why should the product go away, just keep selling the drops. Maybe your not cheeper, maybe you are, try to find some value added way to be different like bundles (notebook/pen/ink set).