Ninway J said:
How much should life be valued? If you're talking purely physical, then that would remind me of this interesting number that someone or some people calculated of how much is a human body worth. I can't recall the exact study or number, but I think they figured out that the entire human body would be worth around $21 million. Maybe someone else knows more of this than I do.
Although it may sound blunt, cold, sterile and abrasive, people can be seen as valuble on many levels; such as material to be sold (organs, blood), labor force (ability to perform a valued service), as breedstock (ability to produce more people of value), for beauty (the body, mind or words as art for art's sake) and finally as a general investment or potential asset to all humanity (ability to perform acts of great importance in the future). As is the trouble of assigning value to anything, it's only worth what someone will pay for it with respect to time.
There are two interesting little annecdotes that relate well to this.
The first is that if you disected a healthy human body and sold off the parts in decreasing complexity (organs, then tissues, then left-over fulids, then ground bones) at mean black market or open market values the human body has a distinct material value, as organs fetch a high price and even bone meal can be sold. That value is close to the $21million that Ninway mentioned.
The second is that most major corporations have an equation that calculates the value of a single human life with respect to the most important thing to them, profit. The equation is designed to help decide whether to fix known problems with a product. In extreme cases this equation is used to find how much money it would cost to recall an item, verses how many people have the item, would likely get hurt or killed, would likely sue, what the average settlement or verdict payment would be and how much profit would be lost from decreased sales and bad press. Easy, see which side will cost you less and you have your decision made for you.
On the philisophical side, I have a distaste for killing any living animal (I even take spiders outside to save them from being squashed by my fiance or, if at my parents, my Mom) and some plants, but I think sometimes "a man's (or woman's) got to do what they got to do", usually for reasons of greater importance (which is a personal judgment call), like survival. Most of you have probly seen or read "Ole Yeller" or one of the thousand other movies or books that require the main character to make a hard decision about life and death.
As for the whole killing plants thing, while I try keep them alive especially for their beauty or edible produce, they are really only alive in a scientific context which we use by default. We kill things that are classified as "alive" everyday with medications, disinfectants, hell, just washing our hands in hot water.
I think the concept of life is sacred, not each individual life, and value (either material or ethical) is determined on an individual case.
) and other "influences" seek for the "self" and when that happens we become offended, disrespectful, uncaring, spiteful, hate and all other things which cause human misery. We do it to ourselves and to others. 
