A friend is upgrading from an integrated graphics card to a 9800GT (his 8500GT broke a few weeks ago). He currently has a generic 350W PSU installed by his tech guy a year ago. His tech guy now tells him that he should buy a generic, dirt cheap 450W Octigen PSU to handle the new card. I have told him that it is far safer to get a reputable brand, 450w-500w PSU to handle the new card, and give him a bit of headroom for more powerful components later on.
Am I right to be worried, or does his tech guy know what he's talking about?
Yes you are right to be worried.
No one who really knows hardware would ever suggest getting the cheapest value PSU you can locate
If you get one, you are just asking for trouble.
Value PSU's almost always overrate how much power they can put out.
The power they can put out is normally very noisy, so much so that a sufficiently cheap PSU can cause system failure.
As your value PSU has very low quality internally, when it fails it will probably surge voltage and take the rest of the computer with it.
Tell your friend to get a QUALITY 400w+ Corsair, Seasonic, PCP&C or Antec Earthwatts PSU.
A PSU like that will have no issues running his system.