I came across an eBay tool that's useful for both eBay buyers and sellers. It's a Firefox extension that adds a column in in eBay searches that totals up the price so you don't have to add up shipping and the price of the item on your own. You can then sort by this column to see the real deal quickly. Here's how they explain it on the ShortShip site:
"Just install this plugin, go to www.eBay.com (or eBay UK, CA, DE, AT, or AU) and do a normal search. The plugin will add 2 sortable columns based on total cost. This plug-in does the following:
* Adds a total cost column to your ebay search results. Just use eBay like normal! (see screenshot!)
* Converts all values to the same currency, so you can actually compare things properly!
* Allows you to filter feedback, so you can see only their negative comments
* Allows you to report excessive shipping to eBay with one click
* Filter results by a shipping range that you specify"
The utility for buyers is obvious, but this tool is also helpful for sellers. You can quickly see how your products are stacking up against competitors and then make some decisions about future strategy if you're not selling at the rate or profit level you expect.
Here's the URL: http://www.shortship.com/
The way this thing installs was a little unusual (at least for me). You have to drag the downloaded file - which has the extension .xpi - to an open Firefox extension window. That installs it. I didn't know about that little trick.