WOW! You look aside for a minute and when you turn back you've found that your campsite has been avalanched over!
Interesting how much passion this discussion engenders. Could there be an underlying sense of guilt about the whole money thing?
It's funny how caught up people get about two concepts that seem to take over our whole lives: money and the clock. Both are invented, virtual concepts that merely act as representations of our perceptions of relationships with other people and the world around us. They don't actually exist except in our minds. Even the cash in your hand is just a promissory note for trading with another person, while the clock is just a measuring device that arbitrarily divides up the space of a solar revolution.
Perhaps it might help to look at the origins of buying and selling, when it was simply named bartering, when money wasn't used. Even today when you barter (which is what eBay is all about) you judge the value of something according to how much the other person wants it, or compare it to how much you value something that the other person is willing to give you back in exchange.
What I am trying to say is that nothing in the world has any monetary value at all; it is purely arbitrary how people come up with the prices of things. If you saw an ancient earthenware figurine lying in the sand somewhere in the desert, which at one time was a plaything for a girl in a society thousands of years ago, what value would it have? Or if you walked into a village in New Guinea and a man there asked you to give him your Cocoon Jacket in exchange for his headdress, what would you consider a fair barter? It is the same for our things.
So when you walk into a thrift store and see an Arcteryx Gamma jacket for sale for $10.00 it is the arbitrary determination of many factors that brought it to that position. Someone decided that is what it was worth. There is no ethical debate, only a serendipitous occurring of events.
Would I feel bad about buying something at a ridiculously low price? Not at a thrift store. If I were standing at a garage sale and a little old lady who didn't know better about the worth of her recently deceased son's collection of UL goods which she was selling for just $20.00, well, I'd think better of what I was offering.