Is it permissible for the suitor to demand the value of the dowry (15,000 EGP) instead of the gold itself upon the annulment of the engagement, knowing that this amount is the original purchase cost of the dowry?

The jewelry (shabaka) must be returned to the suitor if it was presented as part of the dowry (sadaq). The actual item must be returned if it is still intact. He is not entitled to claim its value unless it has been damaged. If the fiancée agrees to return its value, there is no harm in that, and it does not constitute usury (riba). It is permissible to pay the value of the gold at the time of repayment if it was not a pre-stipulated condition and was done with the mutual consent of both parties.