Yes, assuming that the fruits of your labor that was bought for $10 is another luxury (say a bottle of wine) instead of a necessity, then that person also killed $10 worth of people. Because suppose he had bought $10 worth of mosquito nets, then you could have worked as a mosquito net maker instead of a vintner, and you still would have gotten the $10. The two of you could have saved $20 worth of people, so not doing that is equivalent to each killing $10 worth of people.