A Seattle University study examining the costs of the death penalty in Washington found that each death penalty case cost an average of $1 million more than a similar case where the death penalty was not sought ($3.07 million, versus $2.01 million).n its review of death penalty expenses, the State of Kansas concluded that capital cases are 70% more expensive than comparable non-death penalty cases. The study counted death penalty case costs through to execution and found that the median death penalty case costs $1.26 million.