A lot of people say money isn't that important to them, that is fair enough and I can relate.
OK, people can say a lot on the internet, but if you´d know me...
But would you like to see poverty eradicated in third world nations?
(I see, that´s where you are going. When you said "kill for money" I was naturally thinking of money for my private purposes.)
Yes, I´d like to see people in third world nations being better off.
What if the money offered was enough to acheive that (theoretically)?
I can´t say that that wouldn´t be a tempting goal. I´m glad this is so unrealistic that I will never be in this situation.
Tell you what: There´s always a way of reframing things. Just as you framed the problem as "killing for a price" (which I think is a bit an arbitrary way of framing it in view of the complexity that it now turns out to be), I might be able to reframe it as "killing to avoid greater harm". I might. I think I won´t. But this is how rationalization works. And rationalization would have to be a part of my decision in this scenario, anyways.
That said, I don´t think the difficult part in this rationalization would be to remove the "that´s my price" part. My ethical dilemma would lie somewhere else.
I can´t fathom myself killing a human, and for me the "greater good" argument ends at killing.
Something else: I don´t even give all the money I do not urgently need to the poor. So what makes me of all the authority when it comes to others´ sacrifices for this greater good? If I were honestly so concerned with these problems I would do all I can right now, wouldn´t I?
If I felt one man dieing is justified by saving more persons I would even give all my money to the third world and starve myself. I am sure the same amount of money I need for food would feed 10 if not 100 persons over there. So I quite apparently not willing to die for the greater good (and not even far less than dieing) - so who I am to decide that someone else has to?
And what if the person who's head is on the line has committed unspeakable heinous crimes, and will very likely commit more?
Not a significant factor.
And what if you had a 99.99% chance of getting away with it (nothing is 100%)? Would this make you consider the offer in theory?
Irrelevant. If I felt that would be what needs to be done punishment would not be my concern.