In 2004, Israel exchanged 400 Arab prisoners to get 3 of its own back.
More recently, there is purportedly a deal in the works to exchange 1000 prisoners for Shalit.
Being able to make a 5 for 3 deal, or a 21 for 8 exchange might just show the Arabs as good bargainers, or lead to suspicions of the relative importance of the individuals. But at exchanges of this magnitude, little more needs to be said. One culture values its citizens, the other does not.