The Inventory module includes a set of Conditions that complement Game Creator's and allow to check whether an Item can be bought, if the player has a certain amount of items, etc...
Checks whether an Item or an amount of Items can be bought with the current amount of currency.
Checks whether the player has at least the amount specified of currency.
Checks whether the player is carrying at least the amount of specified of items.
Checks whether a combination of two Items will result into something. If no Recipe is found to contain these two Items then it returns false.