Psalm 116:15.. "Precious in the sight of the Lord is the death of His saints." You may substitute "precious" for "costly". Death is the enemy, and every son of God who goes to the grave is one less voice to help the world recognize what is truly right and important. God apparently considers that a big deal, else He wouldn't have said it. You nailed it, death IS an enemy, but it will be destroyed.
Excellent post,
Scorpi