Is the husband obligated to pay the deferred mahr (Sadaq) with the same value mentioned in the marriage certificate (30,000 EGP), or with its current equivalent value (approximately 80,000 EGP), given that the marriage took place six years ago?

The basic principle is that the husband is obligated to pay the deferred Mahr (postnuptial dowry) in the currency agreed upon in the contract, as long as it is available. He is not required to resort to paying its value due to a change in the currency's value or rising prices.

However, some scholars hold the view that one should resort to paying the value when the currency's value changes excessively, and they differ on the standard for what constitutes an excessive change.

Therefore, if the currency's value has changed excessively, the preponderant opinion is that the husband should pay the value of the deferred Mahr, unless a reconciliation is reached between you on something else.

And Allah knows best.