The official Japanese Harry Potter and the Goblet of Fire web site has some merchandise tied in with the movie for sale. Some of the new items include a golden Goblet of Fire, a golden egg necklace and wands for Cedric, Viktor and Fleur. As of now, none of these items are for sale anywhere else but you bust have an Japanese address to purchase.
You can go to the web site to see all the items for sale.
Thanks to Sara for the tip.