Explain this?

I think we used to say; " not for a million bucks", when asked or told what to do, and we were totally against it. Or, "I wouldn't do that for all the gold in Ft. Knox"
Ima guessing they are related.
But since it's a double negative, maybe it just means
" pay me something, I ain't doing it for nothing."
IDK, jus guessing.
Ha Ha. These young people today don't even know what a double negative is. When I got out of the Air Force, I worked as a Western Auto Assistant Manager for five years while I went back to school. One day one of my guys said he wasn't going to lunch because, "I aint got no money." I said how much do you have. He repeated "I aint got no money." I tried to explain to him that he was using a double, but after about five minutes I gave up.