What financial compensation is the husband religiously entitled to from the wife’s family after her refusal to complete the marriage on the wedding night, given that the marriage expenses exceeded $30,000, whereas if the separation had occurred during the engagement, the costs would not have exceeded $10,000?

If the marriage contract has been concluded, it is incumbent upon the wife to move to her husband's house, otherwise, the angels will curse her. If the wife dislikes staying with her husband, she may request a khulʿ (divorce initiated by the wife) by returning the mahr (dowry) that the husband gave her. The husband is obligated to accept this and separate from her. Khulʿ is valid even with more than the paid mahr if both parties agree to it, and this is the view of the majority of scholars. It is not recommended for a man to take back more than he gave her, but it is permissible, though disliked. Your brother may request the mahr and the expenses he incurred for the celebration, especially if the wife is wealthy; however, if he foregoes it, that is better. The period after the marriage contract is not called the engagement period, but rather the contract period.