Have you tried showing him the performance of A64 vs. P4? For $200 you could get:
a. A64 2800+ socket 754, chaintech mobo (see thread #1 in this forum)
-or-
b. P4 2.4A 533 fsb, Asus i848 mobo (see newegg.com)
Now compare Doom3 performance
here (see the 2.4C with 800 FSB) though in other games the A64 2800+ performs about the same as a P4 2.8 - 3.0.
If your friend has an extra $100 to spend [compared to A64 ] , the intel P4 2.8 is a decent chip, and you can get socket 775 with PCI-E support to get a cheap 6600GT video card.
For a P4 2.8E, i915 chipset mobo, 2 x 256 DDR, pci-e 6600GT expect to pay about $480.
Add a nice case (Sonata $100), hard drive, DVD-ROM, DVD-burner (NEC 3500a), etc. to the total price for a complete system.