Does zakat become due on the original price of goods whose sale is difficult, or on their expected profit?

Goods offered for sale (trade goods) are not subject to Zakat on their actual items, but rather on their value. Trade goods are appraised at the end of the year (Hawl), and the amount of Zakat due is a quarter of a tenth (2.5%) of the value of the goods. Profits are added to the original capital of the trade and Zakat is paid on all of it at the end of the Hawl.