This video shows how to view the "best offer price" that a seller accepts on an eBay auction. This could help you familiarize with the going rate of an item, or if a seller has a similar item for sale, you can possibly save a couple of bucks knowing the general range he/she wants.
https://www.youtube.com/watch?v=ylU7h0oiWZ4&feature=c4-overview...
Hope it helps!
Mike