Are you sure he said that? He said that he was looking into buying an AGP 8x card, but he never said he actually had an AGP 8x slot... Maybe I just overlooked it... Especially since his computer came with the internal graphics card, it might not have an AGP slot, or if it does, it might not be AGP 8x. I don't know though...
By the way, I really don't recommend you get the FX 5200... I had one and it didn't get the job done for me. You might want to save up a little more money and look into a nicer graphics card, because you'll be happier in the long run. Patience, my friend, patience is the key. To get my 6600 GT, I had to have it... I waited about 3 months to get it! That was a long time for me...