This is an online store selling through eBay. I recently purchased a book I had been looking for from this store.
They have a good selection of second hand items; books, computer games, magazines, games and toys, videos & DVDs, records/CDs etc. (even some old cameras, if you're a collector).
At the moment they have over 600 items for sale, all with a buy-it-now price, rather than auction-style. All are listed with free postage, so this cost is obviously accounted for in the sell price, so you know straight away what the item will cost you.
The book I bought is in very good condition, just as described, and I received it through the post within a few days of purchase. At only $5 including postage, I thought this was a bargain.
They have a 100% positive feedback rating from customers, with over 5000 ratings, so have a proven reliability record.

Approximate cost: $5 post-free