LCD monitors vary a lot. My Viewsonic VG150 is fine for games. Refresh is fast.

Question is: did the guy try to sell you a flat screen CRT? Or was it a LCD monitor? For the money, I'd guess it's a CRT. CRT's usually fine, though there are still some dogs out there. Important: Check out the screen at your desired resolution and refresh rate (ask the sales droid to set it up at least 1024x768 and 75Hz refresh).

There's hardly ever a need to buy the latest bleeding-edge stuff. You pay lots of money for stuff that's old hat in 3 months. Get something that's 6-12 months away from "brand new" and it will kick butt just fine and cost a lot less.

FYI you can get a machine which runs G2 just fine for < $600. All you need us a Pentium 2 450mHz, 128meg RAM and a good graphics card.