Death Sentence Supporters: Would you still support the death sentence if it costs more than a prison sentence?

You raise an interesting moral dilemma. What would your reaction be (and the people who support the death penalty, especially on economic grounds), if a close relative or loved one was falsely accused of a crime, was put to death and it later transpired that he / she was in fact innocent. A huge number of people in the past have spent many years in prison for crimes they didn't commit and were later released, would your conscience have allowed you to put them to death?