AGP or PCIe Setup?

I am going to build a new AMD based computer soon, and I don't know if I should pay extra for PCIe. I was looking into a 9600 for an AGP setup, and a x300 for a PCIe setup. Does PCI express give you alot better performance? Is it worth it to pay over $50 more for a PCI express board?

I would say it is time to go for PCI-e. The performance now will be no different than an AGP system but upgradability is much better. Don't get an X300 though. The X600 pro performs more like a 9600 AGP and costs less than a 9600XT.

http://www.newegg.com/app/ViewProductDesc.asp?description=14-102-417&depa=0