It only takes one extra click to get to the desktop on Windows 8 ! and Microsoft are supposed to be issuing 8.1 soon to address users' complaints about the interface (speculation being that this will bring back the start button).
Didnt really read all of this thread, but just as a ballpark figure...
I managed to build my own for about £600. I managed to get:
I got the Case, Motherboard, Power, DVD and Wireless Card etc too included in the £600
I spent AGES contemplating whether i should risk building my own, or just buy a pre made one.
Both costs were roughly the same, but I think building it myself meant I got that extra bit of RAM, and SSD instead of a HDD and better quality components