Agreeing on specifying the amount of the Mahr

Q: We are a tribe in the south of the Kingdom of Saudi Arabia. Some people were so ignorant that they used to fight and dispute, to the extent that even brothers do not visit each other, even on the days of the `Eid (Feast). However, with Allah's Favor, and thanks to the encouragement of their sons to love each other and do good, they agreed to become united and consult each other. Having reconciled, (Part No. 19; Page No. 48) they decided to hold a meeting in one of their houses to discuss some matters. The meeting was held after the attendance of the majority, and they agreed upon the following:First,The Mahr (mandatory gift to a bride from her groom) should be 30,000 Riyals for a virgin, and less than that for a previously-married woman. Walimah (wedding dinner) should be served according to the need, with a maximum limit of four slaughtered animals.Second,Quitting their previous customs at the time of death; they used to slaughter animals and feed everyone. Now they only offer condolences for three days without slaughtering animals, and there is no harm in giving a Sadaqah (voluntary charity) after three days.Third,They have agreed to raise a fund, such that each one pays fifty Riyals every month, in case an emergency happens, such as an accident that occurs to one of the tribe or is caused by one of them, that results in deaths or injuries. In such a case, the damages are paid from the fund. In case it is not enough to pay the damages, the rest is paid by the tribe in installments. However, if the dead or the injured is one of the members of the tribe, it is their own business; they can either forgive or accept the damages. If a fight erupts between one of the members of the tribe and another person, and blood is shed, indemnity is paid from the fund after making attempts to solve the conflicts. (Part No. 19; Page No. 49) If the fight is between two members of the tribe, they have to forgive each other. If someone's house is set on fire, people help him and give him a sum of money to find shelter for himself. What is the opinion of Your Eminence on such matters? Please advise, may Allah reward you.