dith quoted above tell us few things:
B.6.2.1. There is no specified rule to fix the amount of Mahr for any marriage; it depends upon financial status of the groom.
B.6.2.2. From the hadith of Umar bin Al-Khattab (RA), we come to know that the Prophet (PBUH) used to give 12 Uqiyyah as dower to his wive (in other narrations it is reported as 12.5 Uqiyyah). One Uqiyyah equals 40 dirhams of silver. If we take average weight of one dirham coin of silver as 3 grams (the weight ranges from 2.975 to 3.06 grams), one Uqiyyah of silver will equal 120 grams of silver in weight. Therefore, Mahr given by the Prophet (PBUH) amounts to (12.5 x 120) = 1500 grams of silver (i.e. 1.5 kg of silver). This can be taken as a reference by all Muslims for an ideal equivalent value of Mahr for a marriage.
However, it can’t be made as a fixed standard, as we see from the hadith of Sahl bin Saad that the Prophet (PBUH) asked the man to pay even an iron ring as a Mahr. Therefore, there is no lower limit for a Mahr, but for people who can afford, it is good to make their Mahr as an amount equivalent to 1.5 kg of silver.
B.6.2.3. There is no upper limit for the Mahr, but it is recommended not to make the amount too high and keep it at a reasonable value, preferably equal to the amount paid by the Prophet (PBUH) to his wiv