Why buy any at all?
No matter how "cheap" they are - although any family that was given the cost of a single drone could retire and live in luxury for the rest of their lives - they accomplish nothing except to build up enduring reservoirs of hatred against us. You and I may know it's just a handful of deranged politicians and army officers who are responsible, but to the victims' families and friends it's "the British" or even "the Anglo-Saxons" in general.
Biting the hand that feeds IT
