What is the measure of the dowry amount the husband seeks reimbursement for from the breastfeeding wife?

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The husband must seek reimbursement based on half of the stipulated dowry (half of what was named/agreed upon), not half of the fair market value dowry (Mahr al-Mithl). This is because he is only reimbursed for what he paid, which was half of what was stipulated for her. Al-Shafi'i argues for half the fair market value dowry because it is compensation for destruction (of a right), so value should be considered, not the agreed price. However, the right to marital access (Bida') has no value if the wife kills herself, apostatizes, or breastfeeds someone invalidating the marriage, as no compensation is due in those cases. Therefore, reimbursement here is limited to what the husband actually paid. If compensation were based on the value destroyed, he would claim the full fair market value, not just half, as the destruction was not limited to half.