A Man-price relates to Old Norse and Early Anglo-Saxon ideals in which the warriors were of value to a King and should one be killed in a conflict other than a battle it was understood that the party responsible for the warrior's death would have to repay that value to the King as a fine, if you will, if they were to avoid making enemies. The idea is expressed in Beowulf, Grendel as characterized as evil for (among many other things) never paying the man-price for the men that he slaughters.