Need suggestions for budget upgrade

[BlackUp]

I have an OLD system and it still serves me quite well but I would like to play some modern video games with it. As it is, it can barely handle Civ4. I'd like to replace the MB/CPU/GPU and add 4 gb of memory for ~$400. I would prefer to go even cheaper, say <$300, but I know this crap is EXPENSIVE!!!

I'd appreciate any and all suggestions. I'm open to just about anything.
From my research I noticed that Newegg has the following: E4600 core 2 duo 2.4 ghz + Gigabyte GA-EP45-DS3L for $190 after rebate.
Could I get 4 gb of memory for 50$ and a decent GPU for $160? Would that combo be adequate?

Here is my current system (with an * next to components I intend to keep)
CPU- AMD Athlon XP 1.2 ghz
MB- an old ECS K7S5A MB (im 99% sure its this one: http://www.hardwareanalysis.com/content/article/1354/)
GPU- ATI Radeon 9700 pro (AGP)
*Case- old metal ATX (can take pics if necessary)
*Power supply: PSU RAIDMAX RX-380K 380W RT
*Monitor: Acer AL2216W (1680x1050)
*Hard drives: Maxtor 6Y080P0 (80gb, 7200rpm, IDE), Maxtor 5T020H2 (20gb, 7200 RPM, IDE)
*Sound Card: M-Audio Audiophile 192 Sound card - 192 kHz - 24-bit (PCI)
*Wireless adapter: D-Link WMP54G (PCI)
*Keyboard, mouse, etc
*Plextor Plexwriter 12/10/32a (I guess I'll need to pony up for a DVD drive as well but I'll leave that for later)

[The Wise Monkey]

I'd recommend going for the E7300 for $120, and this ASUS P5Q motherboard for $88 after Mail In Rebate (MIR):

http://www.newegg.com/Product/Product.aspx?Item=N82E16819115132

http://www.newegg.com/Product/Product.aspx?Item=N82E16813131335

This RAM is a ridiculously low price - $25 after MIR for 4GB of excellent quality:

http://www.newegg.com/Product/Product.aspx?Item=N82E16820145184

This GFX card is $110 after MIR:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130380

So that comes to $363 for a set of excellent components. You might need a new PSU as well to cope with the new video card and CPU - this PSU is excellent value at $30 after MIR, taking the total to $393:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817341012


If you wanted to save some money, that deal you mentioned is very good value and comes out at $40 less than my suggestions, which you could spend on a better GFX card or just keep in your pocket. :)