Is running out of things to buy such a bad thing?

There are almost always local farmers and meat producers for food -- you'll get fresher, healthier, better tasting and cheaper food while getting the warm and fuzzy feeling of supporting the local economy and not contributing to the pollution of intercontinental food transportation.

The rest is mostly just aquisition. The vast majority of what we buy isn't a need, it's a want. McDonalds french fries included. If you want McDonalds to stop selling so much junk food, about the only thing you can do is stop buying it yourself.