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.
If, after explaining this to him, he still wants a cheap PSU, show him the following link.http://corsair.com/cinema/movie.aspx?id=622747