As a seller of almost 3000 items on eBay we still wonder if it's worth the time, listing fees and effort to sell something we haven't sold before on eBay.
A simple method that helps us to decide if our item might sell if we list it.
Type in the search window the item name you want to sell, by typing fewer words and being specific can save time in your search, ie. brand name, material, country, can narrow your search by thousands of listings. Let's say you have a Sony Cybershot digital camera to sell; if you type in the search window digital camera, you will get search results for thousands of cameras, refine your search to key words like Sony Cybershot, the cameras you are interested in will come onto the screen. Click ending soonest, you can then tell if a camera like yours which is ending in a few hours or days is going to sell or is popular by the number of bids on the cameras going off auction. You can also see how the successful seller listed their item, ie; category, key words in title and starting price.
If the item we want to sell has no bidding going on in the ending soonest section of a similar item we don't post it as the probability of selling it is slim.
Hope this helps as there is no market for some items and is a complete waste of time.