This is the first time I saw this thread... Why is everyone around here so power hungry for PSUs?
Well my original suggestion was 350-400 Watts. In the past I have built many machines with a 350Watt supply, if only because that was what came in the case. I have had no PSU problems, and take the view that the manufacturer gives a warranty and decides to put a 350 in the box, then they probably know what they are doing?

Recently, the cases I have bought have had a 400Watt supply, which possibly reflects more power hungry components. Once again, it seems to be the default value these days.

I go with ZT3000 on the idea that not all PSUs are equal in quality. That is why I like a reasonable safety margin, and tend to go for cases around the $65-$70 mark.

Also remember that your machine is not running at full belt all the time.................I just looked at the PSU in a new case and it is 180~400Watts. The concept is one of a safety margin, or margin for error. Most equipment run at half capacity will last longer and run better than something that is at its maximum capabilities.

As there is little difference in the price, why take the risk?