There are purchases you need to make, and then there are purchases that you just want because it would be nice to have. To identify the latter more clearly, ask yourself if the reason for a purchase goes beyond "Wouldn't it be nice?"
Picture: Kirsty Hall/Flickr
There's no limit to the things that companies can and will sell you to make your life a little easier. A device that cuts vegetables in half the time, a chemical that makes rain roll off your windows easier, a car charger that's also a flux capacitor. Some of these are more useful than others, but they all fall into the category of "Wouldn't it be nice to have?" for most people. As personal finance blog Frugaling explains:
"You know what would be nice" is the reason Ikea, Target, and other big-box retailers exist. They perfected the art of the ensemble. It wasn't enough to get/have a couch; now, you needed the accoutrements. They suggest "what would be nice" and show you the pairing. Their catalogues and stores are expertly laid out to exemplify an orgiastic group of accessories.
A small rug could complement the dining room. That watch would make this outfit POP. This lamp shade would make my room cozier. This shirt would be great for a night out.
"You know what would be nice" is the dream hypothetical that only lives in marketers' models. Realising this is one of the most painful lessons in consumerism. No matter how many "nice" things I own, the question will continue to putz around my little mind -- craving me to cave and spend.
This isn't to say that all purchases that aren't basic needs are frivolous. That windshield treatment for rain would do wonders for someone in Seattle. And maybe you bake enough to warrant an industrial grade mixer. But if the best reason you can come up with for a purchase is "Wouldn't it be nice?" then chances are there are better things to spend your money on.