>So maybe the Mugger should up the price -- why ask for a measly 10£ if it only can be done once? And now we are in familiar, but arguably unavoidable, "icky" territory of assining cash value to the physical well-being of individual humans

From the post above mine. This raises another interesting question, where there is a threshold variable. From 0 to x dollars life has a value. At X dollars the cost to self passes the danger to self and the icepick becomes an attractive option. So the mugger does in fact start the process of assigning a value to a life. Then the individual (or more realistically the community that looks away) decides at what point that the danger to self and the value of the muggers life cross. So really it wanders into the territory of the most utilitarian of pursuits, the judicial system.