This could be the difference between cost and the selling price. For example, a retailer may markup its cost by 50% to arrive at a selling price. In the retail method of costing inventory, markup is used to mean the "additional" markup from the original selling price. For example, an item with a cost of $10 might normally be priced at $15. However, because of the shortage of this item and because of high demand, the retailer sets a selling price of $17. Sometimes markup means the $7, but sometimes it means the additional markup of $2.