If I had the choice, I will always buy from an individual (or company) that has a reputation to protect, which I normally call a 'reputable dealer'. It will almost always cost a bit more but it means reliability or replace-ability if it's defective (guarantee). You do not generally have that when purchasing from eBay.
I do not have one of the power supplies in question, but there is nothing wrong with a switching power supply if it's designed and built correctly. The link 'RT2020' provided shows a power supply that is reasonably priced and from a reputable dealer who has a reputation to protect so I would certainly consider it if/when I have to replace my present power supply.
All power supplies commercially sold have certain standards that they are rated for. One of those standards is for electrical noise. If it doesn't have that standard on the label then you can't be sure if it's 'quiet' or not. So, if it isn't advertised as having that standard then ask. If you can't be assured it's quiet then I think it would be a reasonable idea to pass it by.
None of this is a 'revelation', it's fairly common knowledge...
- 'Doc
Opinion:
eBay is a good place to 'dump' stuff. There are no guarantees worth their salt on eBay except from 'reputable' dealers. The majority of people selling things on eBay are not 'reputable'. I apologize to those that are, but they are not typical.
