What's the best way to avoid wasting money on equipment? [closed]

Question

Budgets usually have tighter limits than wish lists. What strategies can be used to avoid wasting money on equipment?

By "wasting", I mean spending on an expensive item of photography equipment to solve a problem and then finding it frequently fail at solving well the problem it was supposed to tackle. The inability should be attributable to the product's design, not breakage of a specific item or inexperience with such gear.

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_{I felt a recently closed question about useless accessories had some potential for taming the widely spread constant need for new equipment and bringing out some marketing hype, so I'll try to ask a similar question in a more constructive way.}

Answer

I don't have a personal tale of great gear disappointment, but I offer some general advice.

Be clear what problem you are trying to solve

Are you buying a new body in order to become a better photographer? That's probably not going to happen. On the other hand, buying a new body to get improved noise at high ISOs may well work out nicely for you.

Reviews

The internets are full of reviews, even for pretty esoteric bits of kit. Find a review of the specific item you're considering. 10 minutes doing this might save you from disappointment.

(Update inspired by @jwenting and @imre - see comments):
Consider how credible reviews are. Finding several reviews on different websites may help to work out which are reliable. Amazon is a good place for reviews because you can often get several opinions together.

eBay is a Gamble

Buying second-hand is a great way to save money, but sometimes it will backfire on you. It's just the law of averages. If you accept that it's a gamble, then you can save some heartache.

... Just a few thoughts.

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