A book printed for trade: at what value is zakat to be paid?

Question

According to what calculation is the value of trade goods to be assessed for zakat: at the original cost, or together with profit? For example, Zayd had two thousand copies of a book printed for trade. Each copy cost one rupee in original expenses, without profit, i.e. the original value of the whole stock came to two thousand rupees. However, Zayd fixed a market price of three rupees on this book, while he himself began selling it to other traders at two rupees per book.

Answer

At the completion of the year Zayd has eight hundred copies of the trade book, and apart from these he has no wealth — cash or the like — in which zakat would be wajib. So now zakat will be wajib only in the copies of the book that are present, not in the whole of the wealth that he spent to print the book, nor in the salaries and the like already spent, nor in the sale…

Source: Fatawa Mahmudiyya

Preview. The full text opens with JavaScript enabled.