Not at all, I ran Arma just fine on my- Old HP Asus board, 2.4 GHZ AMD x2, 3 gigs of ram @ 533mhz, custom copper cooler with fan with way to much voltage going to it, 250 gig hard drive, Lightscribe multi drive, and a XFX Nvidia G Force 8600 GTS XXX overclocked. In fact I was able to turn settings up to full, w/o anti aliasing and VD set at 1200m.
You can build a system exactly like this for around 200 to 300 dollars....lol.
For 600 to a 1000 you could have a full blown gaming rig.
It's way less expensive than you think. It only becomes expensive if you fall for the name brands that are crap, and over price their crap.