[rmvh]

It costs, plus or minus, $1,200 to fly to Bagdad from London.....Where did this human flotsam get the money?

[ewing]

The human shields only needed about 200 pounds apiece for the bus ride.

[CyberAnt]

They drove in double decker buses.

[El Gato]

It costs, plus or minus, $1,200 to fly to Bagdad from London.....Where did this human flotsam get the money?

They didn't fly, they took the bus. (It's quite possible to drive from the UK to Iraq, given the chunnel or a ferry to get you to the European mainland.) From the story:

Two red double-decker buses, which symbolised the hopes of anti-war activists when they arrived to a fanfare of publicity a fortnight ago, slipped quietly out of Baghdad on the long journey back to Britain.