You can't do a GIN your too new. You'll have to wait until you have completed a few auctions before you can do it. It will show up in advance options when you go to post an auction.
BTW if you get verified and show actual ownership of these games (maybe a picture with your listia name on it with the product) you will get better results for your auctions. Free shipping always help's too.. and when you get good feedback from a few auctions that certainly helps. Welcome to Listia.
How does that work? --Remember guys, it may say 10 hours until it's ended but don't worry it will still go on... it will just re-list. . Hoping you know what I mean