Nah, of the recent CoD games it's the only one that's half worth playing.
The gritty brown shooters are getting old, new IP like Brink is what's needed.
Build based around a 1055t, a Quadro FX 560 and 8-16gb ram should suffice and be under 600 quid.
Mind you certain bits of autocad still don't fully utilise multiple cores so could get away with an i3/565 build.