Actually, for what you get in a mac, it's well worth it. Especially if you're a novice to computing, because it's easier to learn on a mac than a PC, because whereas with a Mac, there's only one way to do things - with a PC, there's usually 5 or 6 ways of getting anything done, which can be daunting for a new user.
Plus, you know that when you get a mac, it'll run your software, because it's been developed for the machine.
If you're going to pick on a mac, don't pick on it's price or performance. Pick on compactability - most people make programs for windows, and not macs - which is a problem for a mac user. It used to be that when somebody made a program, there were two installations - so you didn't need to purchase two versions. That might be coming back in, now that most programs are reducing file sizes - which allows a computer to run faster.
You may
think PC's are cheaper, but in reality, you're getting a lot less. My parents bought my brother a Compaq Presario. Sure, it was around £300 and 'brand new' but it doesn't have even half the memory or RAM my computer, or my laptop have.
And if you install something, you gotta think about RAM and memory, and make adjustments for it to work well.
This is why building your own is a good idea....especailly as PC World isn't selling you a computer, it's selling you a garantee so you can only take it back to them. If you use a local company to start with, they'll be lumbered with work, so they don't put the bugs that PC World puts in, meaning less breakdown, meaning you also pay less.
Of course, you could always build your own - nothing beats having almost 10 terabyes at your disposal, especially when you can charge people to store stuff on the space you'll never in a million years fill up yourself.