adafruit wrote:i suggest making a site *and* selling on ebay
I was going to suggest the same thing-- no reason to make it an either/or proposition. If your web site isn't generating many sales yet, then give it some time. In my experience, brand new web sites often don't see very good search rankings, but things pick up after a while as other people start to link to your site (hopefully).
If your product has a unique name like USB Mega Fire Widget, then people searching for it will find their way to your site. But if you're selling generic semiconductors using the manufacturer's name for them, your site will have to be pretty awesome to rank high in Google search results.
If after 6-12 months, you're still seeing far more sales from eBay than from your web site, then I'd conclude the 13% you're paying eBay is a fair cost for the extra sales it brings in.