What alot of people must also understand is the two most primary upgrades needed for any computer is a very good video card, 1-2gigs ram, and a fairly decent cpu.
With a good video card, you can crank the graphics high and use the cards full potential, further taking load off your cpu (That's the idea with a video card) Most video cards today are stronger than some of your 6 year old computers, so in effect spend 180+ on a good video card, and your basicly buying yourself a lil mini computer for all your eye candy needs.
Also with newer graphic function being used IN aceshighII... again, it will utilize your video card more, further taking load off your cpu. That's where the ram comes into play as it will give the video card more time before cpu hit's.
Of course when you have your video card, and ram, then you can take your sweet time getting a better cpu, as mostly that will just help game load time and arena load speed.
1200$? no
350$ maby a lil' more.
Do not under estimate how much more graphic functions being used by the video card can help the game itself run smoother provided your video card doesn't blow.

This next update may prove more rewarding than some may suspect.