Some of us
over-40 simmers who aren't loaded are squeaking by with systems that are not much more powerful than your turnkey Dell... my rig, for example, uses the same CPU and a very similar graphics card (7950). Only 2GB RAM, too, and I use onboard audio.
Not sure how well it would do with FSX, but it runs FS9 maxed out at over 40fps. Good enough for me. I don't do much other gaming, but I've run HitMan and BioShock on it, and they look and run very nicely without taxing my rig.
Maybe knowing that will ease your pain while you scrounge for your dream system...
