This seems like a cool line in Heist (2001), I'm just not sure what it means or what exactly he is trying to say. I get that he wants the other guy to drop the gun or he will shoot him or something to that effect but I don't understand how the line implies this.
There used to be (and maybe still are) pay scales where you put in a penny (years ago -- probably a quarter now) and stand on the scale. You would get your weight and a fortune (like those from a fortune cookie). The machines would like have advertised using this slogan, like a sign on the machine.
So the gunman is saying, It's up to you to decide whether you will live or die. That is, your fate is up to you at this moment.