There are certain items that Blizzard inserts into the game at certain times of year that become extremely popular for some reason or another. These seasonal items, usually released for major holidays are worth even more in the off season and can make you a decent profit if you know how to work the market. First off, when a new item is available, buy as many as the game will allow you to buy. Store all of the extras in your bank or on an alternate character and wait out the season. This is a small investment really. When a month or two has passed, those wow gold will become rare and people will pay decent gold for them. Visit the Auction House and check the going rate. When you are happy enough with the increase, simply sell your backstock and make some extra gold.