In fact, you can be sure that pins ALREADY IN STOCK IN OZ will increase when the dollar fluctuates as the retailers will always claim "the dollar is different now, so it costs us more to bring them in".

Retailers need to replace the stock, so there is some justification in raising the price of stock games. Similarly, when there is an actual price drop on the wholesale price, they are generally forced to reduce the price on an item previously bought at a higher price originally in order to reflect the new pricing.