Exactly... you buy a PC if you enjoy tinkering. People that buy a mac generally have better things to do with their time!
Well... I know what you're saying, but so far as I'm aware - apart from the items you have mentioned all the boards and parts are very much custom because they are built into apples award winning enclosures. Apple lead the computer world in industrial design.
If you were right that they were filled with generic components then they would be cheaper to repair than they are! Not that I've ever had one repaired, but I know it does happen. :o
And yes they do usually come at a premium price, but you do get industrial design which is second to none and should be factored in.

