What upgrades do I need on this PC

[infernus]

I have this parts:

Intel Pentium 4 630 3.0Ghz with HT LGA775
ECS 865G-M8 i865
512MB DDR333
Inno3D Geforce FX5200

It runs fine but a little lag on most new games.Im planning to upgrade some parts I dont want to spend too much that will be 50% of the total price of my PC.

So what should I upgrade? Im thinking of this for the video card.

XFX Geforce 7300GT
http://www.newegg.com/Product/Product.asp?Item=N82E16814150198

or maybe a little increase in budget and for this graphics card:

eVGA Geforce 7600GS
http://www.newegg.com/Product/Product.asp?Item=N82E16814130076

and 1Gig of RAM.

Will it increase the performance of my PC?

 

[Nukem]

increase the budget... ther 7600 is a much better card

 

[talldude123]

another 512MB RAM and the 7600GS would make a nice gaming experience.

 

[COD2_fanatic]

eVGA 7600GS
http://www.newegg.com/Product/Product.asp?Item=N82E16814130076

Patriot 1GB RAM
http://www.newegg.com/Product/Product.asp?Item=N82E16820220058

OR

A-DATA 1GB of DDR400 if your motherboard supports it
http://www.newegg.com/Product/Product.asp?Item=N82E16820211141