(11) And they took all the goods of Sodom and Gomorrah, and all their victuals, and went their way. (12) And they took Lot, Abram’s brother’s son, who dwelt in Sodom, and his goods, and departed. (13) And there came one that had escaped, and told Abram the Hebrew—now he dwelt by the terebinths of Mamre the Amorite, brother of Eshcol, and brother of Aner; and these were confederate with Abram. (14) And when Abram heard that his brother was taken captive, he led forth his trained men, born in his house, three hundred and eighteen, and pursued as far as Dan. (15) And he divided himself against them by night, he and his servants, and smote them, and pursued them unto Hobah, which is on the left hand of Damascus. (16) And he brought back all the goods, and also brought back his brother Lot, and his goods, and the women also, and the people.
(ו) ... אין פודין את השבויין יותר על כדי דמיהן, מפני תקון העולם. ואין מבריחין את השבויין, מפני תקון העולם. רבן שמעון בן גמליאל אומר: מפני תקנת השבויין...
(6) ... We do not ransom captives for more than they are worth, due to Tikkun HaOlam [good of the world]. We do not help captives escape, due to Tikkun HaOlam. Rabban Shimon ben Gamliel says: "[It is] due to the enactment of the captives...
(ד) אין פודין השבויים יותר מכדי דמיהם מפני תיקון העולם שלא יהיו האויבים מוסרים עצמם עליהם לשבותם אבל אדם יכול לפדות את עצמו בכל מה שירצה וכן לת"ח או אפי' אינו ת"ח אלא שהוא תלמיד חריף ואפשר שיהיה אדם גדול פודים אותו בדמים מרובים (ואם אשתו כאחר דמי או לא עיין בטור אבן העזר סי' ע"ח):
We do not redeem captives for more than their value. This is for Tikun ha'Olam, lest the enemy exert excessively to capture people. One may redeem himself for as much as he wants. Similarly, one may spend much to redeem a Chacham, or even a sharp Talmid who is not a Chacham but has potential to be great.
Pischei Teshuvah (4):
Eshel Avraham says that Nachalas Shiv'ah proves that when there is concern lest captives assimilate or be killed, we redeem without concern for the Tzibur's money. Yad Eliyahu says that even then we do not redeem for more than the value. Beis Hillel says that we do when there is mortal danger, for one who neglects to redeem transgresses "Do not profit by the blood of your fellow." One must forfeit all his money to avoid transgressing a Lav (OC Sof 656).
Israeli History
In 1985 1150 Arab prisoners were released for three soldiers captured during the Lebanon.
In 2011 1027 captives were released in exchange for Gilad Shalit.