Less than that of picking up those of your child's.
Well, clearly.
What I'm wondering is: If I come home, and find some guy trying to make off with, say, $1500 - $3000 worth of stuff; is it cheaper to shoot him or let him go? At what point does shooting him cost more than letting him go (assuming there's no danger to yourself or others)?
According to
this site violent death scene cleanup is ~$600 per hour, and I'm assuming it takes them several hours to do a good job; so unless the robber is taking some very expensive things, it may just not be worth it.
Now, if you want to argue that a law abiding citizen has a duty to shoot the robber as they may pose future danger to other citizens.... then we have to factor in time value of money and place some dollar value on innocent strangers' life, take into account the mean time between robberies of the average thief, the probability that any given robbery turns into a murder, etc.... and that's just way more work than I'm willing to put into this.