In order to categorize item's values we regularly update its status as one of the following: unofficial, common, rare, very rare, extremely rare and legendary.
The type is based on the number of copies made, value is a mix between type, age and community feedback.
The value on a item's topic is coloured green is the price has gone up or red if the price has gone down since the last update. If there's a default price set, there's no colour.
Updates will be posted on the item's topic so you can manage your collection easily.