@Fido,
I do not care what 'sets the price.' Setting the price is not what made society as it is today and has really nothing to do with it. A life is not worth a price. Selling or making cotton does not make society as it is today. There were many, many, many influences, consequences, and decisions that made the world as it is today.
Only mass slaughter by war can feed profit, etc? Are you really listening to yourself? America could massly slaughter Australia or Europe or Africa or South America. Do you believe it would push anyone forward? Do you think murdering other societies feeds education or science? You are sadistic. Murdering other people is nothing but murdering other people. There may be a cause, as if fighting supression or a bad government or something similar, but war does not help anyone in general. That's how societies lose money; putting money toward bombs, guns, death tolls, etc. That's a step back, not a step forward. If it fed what you say it does, war would occur 24/7 on a mass scale to help 'science, education, experimentation,' and 'exploration.' The only war that helps anyone is a war that accomplishes a large, majority purpose like removing a leader that surpresses.
Slaves were not a stepping stone, the stepping stone was fixing slavery. War is not a stepping stone either unless accomplishing something that supports the majority. It has to benefit many for anyone's death to really gain meaning in a war.
While the elderly and disabled may cause an imbalance in societies, that does not justify the act or impulse to do away with them. The elderly have worked, fought, and suffered to have the world as it is today for you. If you cannot respect their loss, you do not deserve to breathe yourself. The elderly may not directly contribute to society, but nursing homes and other homes cost a lot of money, as well as around the clock care. They do their share of bringing incomes in for nurses and similar workers. As long as they are benefitting someone, it's not a total loss, and even if they were not, that would be okay too. A person cannot help how their child is born under standard circumstances, and the child cannot help this either. Targeting the weak to play a key role in your less than humane ideas is barbarous.
I agree there is no perfect world and that society will not always be humane. I know of Nietzsche, and even have some of their quotes on my board, but I do not agree that death propels anyone forward without a solid, just cause. As Hemingway put it, “Never think that war, no matter how necessary, nor how justified, is not a crime.” War is not a lubricant, and neither is death, and we should not pretend it so to distort a view into something you want it to be.