it should be possible to somehow quantify the benefit of donating a kidney, on some scale, at least.
From Wikipedia:
Kidney transplantation is a life-extending procedure.[24] The typical patient will live 10 to 15 years longer with a kidney transplant than if kept on dialysis.[25] The increase in longevity is greater for younger patients, but even 75-year-old recipients (the oldest group for which there is data) gain an average four more years of life. People generally have more energy, a less restricted diet, and fewer complications with a kidney transplant than if they stay on conventional dialysis.
In secret, an unemployed man with poor job prospects uses his savings to buy a large term life insurance policy, and designates a charity as the beneficiary. Two years after the policy is purchased, it will pay out in the event of suicide. The man waits the required two years, and then kills himself, much to the dismay of his surviving relatives. The charity receives the money and saves the lives of many people who would otherwise have died.
Are the actions of this man admirable or shameful?