I agree with 'magomago' overall - don't skimp on the PSU if you don't have too. On the other hand, if you are looking to replace a cheap PSU, in a Dell for example, there is no reason to spend $100 on overkill.
OP, do a 'PowerSearch' on newegg and narrow it down by power requirement, cost and quality name brands - FSP, for one, offers quality 350-450W PSUs in this general price range.
Topower/Epower - from what I saw on my brief search - get generally positive reviews, used to make PSUs for Mushkin and may be rebadged Enermax. Take that for what you paid for it - nothing - as I didn't save any of the links and a definitive answer seems hard to come by.
Happy hunting OP 🙂