The pc build here has chosen premium retail parts which Apple do not use parts to this quality of standard because it's not in there best interest to do so they are about making profit so every system they build they never make less then 40% profit on each until.
Because they have a supply line which allows them to squeeze high end parts from manufacturers for incredibly low prices. There are certain manufacturers who barely make anything from selling to Apple any more, but can't drop them as Apple constitutes the majority of their business.
I'm not an Apple fanboy - I've got a Macbook pro, an Android phone, a Windows desktop, and an iPad Mini. I think, though, that they make certain devices - depending on your use-case - which are very good value for money.
The Macbook Pro I bought because, at the time, there was not a Windows machine out there which could match the screen, trackpad, keyboard, or battery life, which for me are four of the most important things on a laptop. The 27 inch iMac is similar. Unless you are a gamer, the quality of key components which actually matter to a consumer - such as the screen - is incredibly high end. You also have the benefit of it being built in a single unit, rather than requiring a box on the floor. I can see the appeal of the 27 inch iMac, and were I to need to buy a desktop now would seriously consider it.
On the other hand, in my opinion the iPhone is vastly overpriced with an outdated OS and screen size. Similarly, the 21.5 inch iMac is not something I can see the appeal of, and I can imagine Apple bumping it to 23 inches sooner rather than later. There's a good argument that the iPad Mini is overpriced compared to the Nexus 7, which is a lovely tablet. Personally, I bought it as the majority of my tablet use is web browsing and document reading, and the aspect ratio of the iPad is infinitely better than that of the Nexus.
In short, they make some products which do offer value. They're expensive, but you get what you pay for. Other products are becoming outdated and overpriced, and need looking at.