If I make an exact copy of you, wait X minutes, and then instantly kill one of you, how big must X be before this is murder? Beats me. I suspect there is no hard line.

I would be willing to undergo such a procedure for 10 dollars if X is a minute or less (and you don't kill me in front of me, no other adverse effects, etc.). If X is 10 minutes, probably about 100 dollars.