Why NEW things?

The other day Andre asked in a comment why we have chosen to concentrate on new things. If our goal is not to add more stuff to the environment, he notes, doesn't it make more sense to shop wisely, buy less, but also sometimes buy new things (he gives the example of the electric car but there are also all sorts of examples where one might buy something new to fix something that would otherwise be thrown out etc).
My first response is that "new new things" IS an arbitrary line. I find it easier to be black and white (and the kids definitely find it easier to be black and white!) with this and to just exclude all new things during this 3 month period. It's easier for us to have a simple and clear no-new-things policy than a "tread lightly on the earth policy" (especially since my mind is so good at rationalizing things).
But drawing this arbitrary line has made me reflect on it. In the first few weeks I was caught up in the excitement (surprisingly, given that we were literally doing nothing!) of buying no new things and I imagined this idea sweeping across the Western world and (in my delusions of grandeur) imagined the world being a much better place as a result. But that's not the case in any sort of easy way of course. I did *see* things differently; we live in a throw-away society and I have seen it so much more clearly in this three month period during which I'm wondering: where does all that stuff go? did we really need it? why do people (my family!) think they need so much stuff? what motivates that acquisition?
In defence of no new things: old things have stories attached to them and I like that; no new things forces us to be creative and think of how we could do things otherwise; while sometimes buying other people's old things encourages consumption on the part of those other people, in many other cases I think those old things would just be tossed, rather than re-used.
I was talking to Ted early on and he wondered about having a policy of buying only used things and things made by someone one knows or made within a hundred kilometre radius of where one lives or buying only craft items. If we did so, stuff would be more expensive but we would pause more before purchasing. Then again, right now I'm reading a book that addresses 19thc poverty issues and at the time there was a great push for mass-produced items so that the poor could afford things that were not otherwise available to them. And so it is not straightforward at all.
In the end, though, I think some combination of cutting one's consumption, seeking, wherever possible, not to add to things in the world, focusing on craft items where possible, and buying wisely probably makes sense.