If you could sacrifice a random stranger and receive a billion dollars, would you? Because realistically, you could save plenty of people with that money, and lead a pretty comfortable life besides. How about a million dollars? A thousand? A hundred? Whatever your answer, you're saying someone else's life is worth less than your happiness. Not that that makes you wrong or evil—it makes you human. Do keep in mind that everyone else is currently answering this exact same question too. So be careful how you value others, since you're about to find out how they value you in return.