500 is very tough to work with, especially with the things your gonna need. New video card, new cpu, and new motherboard for sure, and most likely a new power supply minimum. That also keeping your old ddr2 ram. On top of all that you may need that new case to house your card quite unsure of your current towers dimensions and layout. But heres what I got just looking at barebones. http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.465813
Look for something like this maybe take a second look at the motherboard, the case I will stand by being a very solid buy. It will also support your old ram and has a socket 775 for your Quad Core processor. Also has a new power supply with the case that should meet your needs. Its downfall would possibly be because it wont be able to hold any i3, i5, or i7 (recommended for XIV) processors. $185 http://www.newegg.com/Product/Product.aspx?Item=N82E16819115207
Quad core processor $150
That leaves you about 150 dollars for a video card or maybe trying to find a similar deal with a beefier mother board. Your Hard drive and disc drive you can carry over for sure. Your RAM you can keep. No need for a new monitor, keyboard, or mouse. This is like bare minimum and I am not even sure how it will fair for XIV. Most likely a very minimal system here. I haven't ran any benchmark tests so if anyone has inputs that could probably help feel free to jump on in.
If you interested in an i7 build you will need a considerable amount over your budget maybe around 800-1000 minimum for the jump youll need. At least thats what it was for me when I made my upgrade. My advice, bite the bullet upgrade right. If you can't do it than be prepared to have to upgrade again sooner in the future. Edited, Aug 8th 2010 10:08pm by Zeios