Personally I've always found it hard to justify setting aside much of my computer budget on power supplies, and you can probably understand why too; they're almost always boring grey boxes which live out of eyesight and just get on with their jobs. As long as the £30 supply works you're not going to notice any difference if you pay £100 are you? And that £70 you've saved will certainly let you buy a graphics card or processor that's closer to the bleeding edge.
It's thinking like this that always has a knack of turning on me. When my generic 300W power supply died on me last year, and my just as cheap replacement followed it shortly, I found my self out of pocket to more than the tune of that 'quality' supply I refused to fork out for originally. A good power supply is, of course, about a lot more than just going the distance; carefully regulated voltages help avoid system crashes, their method of power conversion dictates how much electricity they waste and how much they heat up your system and the total amount of power they're capable of converting dictates how many extras you can add to you computer.
Removing this supply from its box doesn't reveal any surprises, it looks almost exactly like any other grey ATX PSU (Power Supply Unit).
Note the single cooling fan on this model, dual fan supplies certainly help cool your system though they do tend to be noisier than most. The power switch on the back is strangely non-latching, making it good for resetting the unit but not turning it off for any length of time.
The cable inlet at the back doesn't try to clamp the cables in any way (to stop them being ripped out of the PSU accidentally)...
...though on closer inspection we see they're clamped well inside the case and the metal around the hole has been bent around to prevent any chaffing on the wires: