I'd look at Half.com. It is a middleman between buyers and sellers of CD's,
books, and videos--but there's no auction like at eBay. Their "warehouse"
is the bookshelves of the people that are selling through them. Their
selling price is not greater than 50% of the average price that other
"retail" sellers are offering. (They show you price comparisons right there
one the screen.)
It is pretty new, and I just started to use it myself, so I can't really
recommend it--except to say that the response from their Customer Support
came within 24 hours and answered each of my three question fully--but I
think I'm going to like it.
One twist here is that the shipping charges (the buyer pays, of course) are
fixed--$1.95 _per item_ for CD's and paperback books, $2.95 for
hardbacks--by USPS. (I don't know about the rate for videos--I never buy
them.)
However, since they are new, their stock of titles is not as great as you
might find other places.
Karlo
P. S. If you order at least three items, shipping is free. (This is only
on your _first_ order.)