My thought on using 'natural' products vs 'chemicals' is that hopefully my body won't see it as a poison-who knows what it can do in the long run.
I also avoid petroleum products, not nesc because petroleum itself is bad, people in Eastern Europe sit in it to help with arthritis, etc, it's the altered, petro-chemicals that worry me, I don't know what do they do to it to separate all the parts.
I had a similar thought the other day after returning $48 worth of body lotion (xmas gift) at a pricy department store. I exchanged it for something a little more practical. I was wondering how much more special the Clarins hand and nail cream is than say, Burt's lemon butter cuticle cream. I think it has to do with how you feel when buying it. The Clarins counter is so pretty and the woman at the counter is usually freakishly friendly, while the kid at the health food store is usually looking at me like I'm a frump juggling a baby and telling a nine yo that he can't open his bribe, um, treat until we get in the car.