I use them, but you are pretty far off, when you say "an identical PC to a XBox for the same price".
Windows 7 alone costs nearly half a XBox. You need to invest at least 400-500 € (600-700 bucks I'd say, but I don't know the pricing in the US) for a PC to play Skyrim on semi-decent to decent details.
My PC is handbuilt, it uses windows 7, I only paid sixty dollars for windows 7.
EDIT- Just checked, the price for the Windows7 I got is now $100, although on my receipt it is $65.98, guess I got it during a sale.
Skyrim on low is still higher quality than the xbox version. I know you can create a PC for $350 that is functionally identical to an xbox because I put together a list of all the components and their prices for a friend not too long ago.