Medieval Jewish communities often were called upon to pony up big bucks to redeem kidnapped kin. In contemporary Israel, it has become standard practice to swap busloads of prisoners for one captive soldier, or even for his remains.
There are limits. Medieval jewish communities never had as high a stake in this as modern Israelis do. In a detailed responsum on the subject that predates Shalit’s capture, Rabbi David Golinkin concludes, “We do not pay excessive ransom… In other words, the public takes precedence over the individual, even if this endangers the individual. Exchanging hundreds or thousands of terrorists for one Israeli encourages kidnapping of Israelis, and frees hundreds or thousands of terrorists who will pick up their weapons and attack Israel. In other words, it endangers the public and should not be done.”