Late last year, I got a PS3 for myself, and I was looking to pick up a few games for it. One game I wanted was Guitar Hero, and I wasn't finding very good prices. I went to eBay, and same thing, there weren't a ton of great prices. I decided to try a site that I've used called fat fingers.
When an eBay seller lists an item for sale, they specify the keywords that go in the listing title, etc. People make mistakes, and if they make typographical errors, the end result is sometimes that they just don't get people to see their item. If no one sees it, no one buys it.
Anyway, fat fingers is a free site that will find auctions that are spelled wrong. For example, I was able to find an auction for "Gutar Hero" when I searched, and it was an auction starting at $5. I bid $5, and no one else bid on the item (because they didn't find it due to the spelling error), and I got a brand new copy of Guitar Hero for $5 plus shipping. When I bought this, this was an excellent price for it.
Note that this works well especially with eBay auctions. If it is a "fixed price" auction, you probably aren't getting a deal, but if it is an auction, you have a great chance of putting in a low bid and winning something.
I am still shocked that eBay hasn't found some way to fix this, because when their sellers lose money, they also lose money on commission.
Anyway, here's the site: