Re: Used power supply a bad idea?
It's like a car really. The previous owner could have thrashed it at its limit 24/7, or they could just use it at weekends and keep it well within its capacity.
I'd advise against it personally, because the price difference isn't *that* much and you know with a new power supply exactly what you're getting. If you must do it then go for a decent brand, not a cheap one - if a decent brand does go poof, it's much less likely to take other components with it.
Save the whales, feed the hungry, free the mallocs.