...assuming that the government was going to do absolutely nothing with said $25 million if I rejected the offer...
It's certainly an interesting question. You'd almost automatically be saving far more lives right off the bat than you'd be sacrificing. Contact a few hospitals and find some patients that need some sort of life saving treatment but can't afford it. It wouldn't take long before you saved dozens of people.
On the other hand, it's obviously incredibly immoral to take life from someone simply because someone else could use it. That's borderlining on socialist policy right there.
In the end, no, I don't think I could. It's never my place to decide who lives or dies, and it's certainly not within my realm of authority to take life from an innocent person in the hopes of saving more people with the rewards from taking said life. Perhaps someone with more socialist leanings could do something like that, but as a believer in Libertarian policies, no.
