I see ads today for $100 and more computer power supplies. Capable of 1000 watts or pure green power. Can you buy to much power? The fact is you can over buy. Your typical computer has a CPU, hard drive, and some kind of optical drive. That only requires a few hundred watts. For $30 or less you can have all the power most of us will ever need.
Years ago for $12 you could buy a great solid built 300 watt power supply. It lasted forever without a hiccup. Those days are long gone. Cheap power supplies are just that, cheap. Even though they may claim to be 500 or more watts they are garbage. I won’t mention any names but if you do a search on pricewatch.com anything under $30 is not even to be considered. Today’s computers require a solid built block able to pass on at least 400 watts of real power. It’s always a good idea to keep one on hand for the day you might need it. Keep your eyes on fatwallet.com for a few weeks and you should see a deal for either a free one that is well rated, or $10 with the rebate. At that price it’s cheap insurance for the inevitable.