[Is Zakat Paid Before or After Selling Expenses?]

Answer: Based on what we set forth—that the owner of wealth has authority over the zakat of his wealth during the interim period, and that it is for him to consider the poor’s best interest—he should pay zakat on what remains after deducting the expenses attached to the goods for the purpose of sale, such as the hire for transporting them, the broker’s commission, and the like—because the poor’s benefit from the zakat of cucumbers is not realized except thereby.
In the marginalia of Sharḥ al-Azhār, from Imām al-Qāsim b. ʿAlī al-ʿAiyānī: “Zakat is after deducting the expenses.”
As for grain and grapes, the preferable course is to give the poor their share of them, for that is more beneficial to them in the immediate and the long term, and in accordance with His saying, Exalted is He: “Take from their wealth a charity…” [al-Tawbah:103]. This should not be contravened.
Yes, paying the monetary value categorically is the madhhab of many of the Imams and scholars of the Prophet’s Household in their discourse.
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1