Does trying an aged serial killer make good fiscal sense?

When you catch a serial killer when he/she is 60+ is it good fiscal sense to go after the death penalty or does the body count comes into effect? With a death penalty case the cost of appeals could reach the millions because you have to exhaust all avenues to obtain a reversal before the condemned is killed. If the person is at such an advanced age that if he lived long enough for the appeals to run its course he would likely die before his/her time in line actually came up; thus nullifying all that money spent on appeal. Wouldn’t it just make more sense to sentence the person to multiple life sentences?