A cpu/mobo/mem/vid card that can run Crysis well (in Off-topic)

I want one, my system can handle Crysis until about the second level, then it starts slowing down significantly. I want a CPU, motherboard, memory and video card that totals out to somewhere under $500. Am I asking too much? I want a motherboard with room to grow, so I can expand it later without too much hassle. Is that impossible? I saw this one: P5E3 Deluxe was mentioned in a few places on the internet, but it's too pricey for me. As far as a video card goes, I've got a GeForce 6800 AGP, but I am just not happy upgrading to another AGP card, I want to take the PCIe plunge. If anyone can help, I'd really appreciate it. :)

Oh, I guess I should also post my current specs, as a reference point:
Athlon 64 3000 Socket 754
PCChips W32 V1.0 Socket 754
1GB memory
GeForce 6800

not familiar with the requirements of the game you mention (though I am sure I can look it up if I try), but if you know what specs you are looking for I would recommend purchasing them from www.mwave.com. Better prices usually than newegg and a lot easier to use.

ASUS M2N-X nvidia nforce 520 chipset ATX form factor 1xPCI-E(x16)/2xPCI-E(x1)/3xpci/2xddr2 w/sata2 raid,lan,usb 2.0 & audio (cpu type:amd - socket am2)
ATHLON 64 X2 4400 2.3G - BRISBANE
KINGSTON 2GB DDR2 667
$180.50 for the bundle


ASUS EN8800GT/G/HTDP/512M GF8800GT HTDP PCI-E 512MB DDR3 w/HDTV & DVI
$279.90

based on the "recommended" from the crysis website

uh, I'm sorry to burst any bubbles, but according to most game review programs and websites, the system that can handle Crysis isn't invented yet. If you want full everything.

And if you want that system be prepared to pay a tad more then 500 USD.