Is there a specific value for the bride's dower (mahr) and deferred dower (mu'akhkhar as-sadaq)?

There is no textual evidence in Islamic law that sets an upper limit for the mahr (dowry). A person of means can pay as much as they are able, even if it reaches a qintar, based on the Almighty's saying: "And if you wish to replace a wife with another and you have given one of them a qintar, do not take anything back from it. Would you take it in injustice and manifest sin?"