AGP to PCI-E, worth the extra money?

I snagged up an ATI X800XT PE which seemed as the best card I could get on my AGP setup. It was $220.00 and I thought that was a great deal. Was it a good deal?

Would it be worth the extra money it to move to a PCI-E motherboard and upgrade my videocard? What would $220.00 get me in terms of gaming power when compared to my X800XT PE purchase?

How much more powerful is a 7800GT when compared to a X800XT PE?

I am just trying to justify upgrading to PCI-E and then a new videocard. I personally don't think it will be worth the extra money but maybe you can change my mind. The only game I am really looking forward to is TESIV:Oblivion.

Any opinions or input would be great.

My system as it stands now:

Asus A8V Deluxe (AGP)
2gb PC3200
6600gt 128mb (X800XT PE is in the mail)
3200+ Venice at 2.7ghz (270x10)
450W Antec PSU

If you compare the same model, like X800 XT PCI-E and X800 XT AGP, there will be little difference. The PCI-E has the "potential" for much higher bandwidth, but you won't see that until probably the next generation of vid cards. The 7800GT is a step up from the X800 XT PE, but not really a big step if you have to buy a new system.

I say keep it. I don't think it's worth it to upgrade it now. Your system is only 1 Generation old compared to SOME PC enthusiasts but definitely one of the best there is right now than 90% of all PC users. I used to have a 2.66ghz/533fsb with Ti4200 and I didn't feel old one bit.