I used to go to Wal-Mart and pick on the computer 'experts' in electronics for fun until it got to be just too sad.  Last time I was in the kid was telling me about his PII-400 with his Voodoo3 3000 PCI....in it's day a nice machine.  Made the mistake of asking him why he went with PCI.  
him: "Cuz it's faster"
"ok.  How so?"
him:  "That AGP slows things down"
"but of course"
him:  "Anyway it's only for geforce cards"
"nVidia has some pretty quick cards now"
him:  "Yeah, but it'll take them years to catch up to the 3FX, er, D, yeah, Voodoo"
"yup, that could be"
him:  "Anyway when I need a geforce I'll just put one in"
"so you do have an AGP slot?"
him:  "No, but I can send it in to HP and they'll install one, it's only 50 bucks"
"you're going to have an AGP slot installed?"
him:  "Yeah, no point getting it now since it's slower.
"ok.  So, be seeing ya"
Sounds like he just sold your friend a HP.  
--Mc