he's already cost us a fortune.
That's very true, both in money, blood, and quality of life. Perhaps it would be better, then, for him to be extradited to the U.S. without a British trial? It's an interesting quandry... on the one hand, he has caused Britain to suffer greatly and Britain deserves the opportunity to exact justice from him. Will this trial be so expensive that it will further erode the British public's appetite to wage the war on terror? Will it send a clear message to his followers that fomenting terror on British soil will not be tolerated or will it merely make him a martyr?
On the other hand, the U.S. has valid legal claims against him as well. "The cleric is wanted in America over a hostage-taking drama in Yemen in 1998 in which three Britons died. He is also accused over the setting up of a terrorist training camp in Oregon and the recruitment of militia to fight Allied forces in Afghanistan."