I would say around 5 cents. Also, the reason prices are 99 cents is because it is a pyschology thing. Someone is more willing to buy something that is 4.99 than if the first digit of the price is 5. They equate it more with being $4 than $5, and thus are willing to buy it. Wal-Mart does this extensively, almost every price in their store ends with a 9, because even though the price should be rounded up, it has been proven that people dont round it up when they are thinking of buying the item.