I think we are all a little off topic here, but I would like to put my view forward anyway.
I think Apple has a more closed off way of doing business where both the hardware and software are more carefully controlled in order to ensure a certain level of compatibility and a certain user experience.
This business model provides certain benefits which have value to some consumers, of course this also has some disadvantages which put other consumers off. They are able to charge a higher price for this added value that comes from using this model.
In terms of comparing processors together against their price - this does not have too much value, as speed comes from a combination of different factors not just the MHZ of the processor. Recent speed tests (from Popular Mechanics, USA) have shown Macs to beat comparable PCs at basic tasks such as booting-up, shutting down and program-launch times.
About the keyboard and mouse - nobody has to buy the expensive apple option, the computer fully supports industry standards and you could buy any third party accessory. In fact to the person who asked if the keyboard used proprietary connections - its almost the opposite way round. The iMac in 1998 really pioneered USB connections to plug everything together in an easy and very compatible way. Their keyboards and mice have been USB since then.
I don't know where you are getting your information regarding having to buy keyboards and mice separately -
a main selling point of the iMac since 1998 is that you get everything you need in the box, and it is very easy/quick to set up and get going. (
current source) The current price for an iMac starts at £799, with a Macbook at £699.
The only thing I can think of is the MacMini which doesn't include any keyboard/mouse - this computer is designed to use all your existing peripherals and just slot in instead your existing PC tower - the price for this is £399.