Sa'id bin al-Musayyib (may Allah have mercy on him) said: For one breast (of a woman) there is half the blood money, and for both the full blood money. [Sahih]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16315
Rabi'ah (may Allah have mercy on him) said: A woman's breasts are a covering for her chest and a means of nourishment for her child; they are like wealth in providing sufficiency and like furnishings in beauty, and injury to them is like a severe wound in its suffering. In my view there is half of a woman's blood money for it. A view similar to that of Ibn al-Musayyib is reported from al-Sha'bi and al-Nakha'i (may Allah have mercy on them), and al-Nakha'i said that for a man's breast there is compensation assessed by a just arbiter.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16316