Good question. - 2 answers
You can refine the search using the advanced search algorithms +, -, (OR) to weed out what you don't want ?
Example: Say I want a Sony CD player but not AM/FM/CD for automobiles. I might try this spec:
sony +cd +player -(auto,car)
this will return all sony cd players but not if the word auto or car is in the description.
2nd answer - I just found out that there is an update available that will also allow you to search within a category. Go to the BidSage update page and download the update. It will still say Version 2.00 but if you add the category number in brackets (ie: ) to a search spec it will search that category only.
You should be able to update the version through the menus.