actually it cost me about £400 all things considered, which is about $650 in current climate
but regards playing wow on it, it's amazing. 27" screen + 2560x1440 resolution = a stupid amount of real estate, and with the LED screen the colours are really nice (as good as WoW can be anyway). Ultra settings = ~80-150fps questing/cities (not tested dalaran), not sure about raids.
to Elektrik : I'd spend 4x that amount to NOT have to use windows again. Combine that with a 27" better than HD display with LED backlit screen -, completely silent running, and an OS that destroys windows, to get anywhere near that you would have to spend a LOT more than I did