A single bullit to the back of the head is cheaper.
It reminds of the scene from Austin Powers, where Dr Evil is talking about how he’s going to kill Austin.
Dr. Evil: Scott, I want you to meet daddy’s nemesis, Austin Powers
Scott Evil: What? Are you feeding him? Why don’t you just kill him?
Dr. Evil: I have an even better idea. I’m going to place him in an easily escapable situation involving an overly elaborate and exotic death.
Scott: Why don’t you shoot him now? I mean, come on, I’ll go get a gun. We’ll shoot ‘im together. It’ll be fun. BANG! Dead. Done.
Dr. Evil: One more peep out of you and you are grounded, mister! And I am not joking!
Sorry, bullet.