I'll try to answer your question --
First, I would say that there is a difference between buying your food from a supermarket, and buying into "consumerism".
Consumerism is all about buying more stuff than you need, buying on a whim, spending more money than you have, wasting money and other resources (throwing away and buying new), and in general it means going completely against what Catholics know as the "spirit of poverty".
The spirit of poverty means A) not getting to attached to material things, especially to the point that they dominate your thoughts, and B) taking good care of the things you have. Part of B) is not wasting something that still has value. Garage sales are a VERY Catholic phenomenon (though I admit I don't know the history of garage sales) because A) items are getting more use and B) someone is able to save money.
So if you only buy what you need -- food, shelter, clothing, and what is necessary to maintain those -- you can hardly be called materialistic. The economy is NOT going to boom if everyone did that. When they say that 2/3 of the economy is fueled by consumer spending, they're talking about BIG MONEY and luxuries: cars, vacations, boats, you name it.
As for the food issue, the more food you can grow yourself, the better. There is an excellent book called "Square Foot Gardening" which I bought on Amazon.com for 50 cents (plus $3 shipping). I learned SO much by reading it, I would recommend it to anyone! The book has sold literally millions of copies, and is probably the most popular gardening book there is. See if your library has it. He really has a system that takes all the hassle, anguish, and depression out of gardening. I am working as we speak to convert MY backyard to use his system (4' X 4' plots, divided into 1 foot squares) I am collecting materials to mix up his special soil mixture, etc. Did you know you can grow stuff on a patio, balcony, or rooftop? He has everything covered.
But even the food you need to buy should at least come from a local source. Farmers Markets should be patronized, since they are individuals making a living. Huge agri-business outfits that do SO MUCH of the nations farming are just running a business, and their food is usually of poorer quality. Their soil is literally a sponge, which they spray a bunch of fertilizer on to force things to grow. There is no organic matter left in their soil.
What I find sad, is that many neo-PAGANS are good at living with less, re-using, doing without, etc. which used to be the realm of Catholics! Then you have Catholics who have gone suburban. It's very sad, because the Catholics should really know better (but I know, no one teaches such things anymore...)
I like to identify what is "suburban" so I can avoid such behavior/products/attitudes at all costs. The suburban way of life is very protestant, but VERY un-Catholic. Catholics are social, friendly, have the spirit of poverty, are NOT into status or wealth, etc. Catholics shouldn't have huge electric bills because their A/C is set too low -- that's wasteful and shows a lack of mortification. They shouldn't have TVs (or at least not more than one!). And on down the list -- pretty much everything you see in suburban life would be remedied by turning to a Catholic way of life.
How do we escape being "good little consumers"? First, by knowing that the consumerist system leads to nothing but misery. When we realize that material things will not make us happy, and find other things (prayer, spiritual reading, family, helping the Church, etc.) to take their place, then rejecting suburbanism will come easy.
There are many answers to be given, one for each of the problems. I would have to give hundreds of examples to form a complete "answer" to your question. Maybe you could be more specific, if I've left something out?
By the way, the author of the original article did NOT seem to have any answers. He is good at describing the problem (as are many rock artists today -- they excel at drawing attention to the wounds of the Modern World) but he falls short when it's time to lead us all to a solution. In fact, the poor man doesn't even do a very good job at bucking the trend (WHY did he do something so dumb as paying $50 for a dog's haircut? My wife cuts my hair for free, and I'm a human being!)
I know very well what the solution is, but it takes a bit of time to explain the whole "system". It's taken from the teaching of the Catholic Church. I'm trying to practice it myself, and it really works! I was blessed to attend a Seminary for a few years, so I was taught well what life is about, what illusions the modern world uses, etc.
God bless,
Matthew