Eh, $110 sounds about right for a four-pipe card. A 6600GT will be (more than) twice as fast, and costs twice as much. So he didn't get a fantastic deal, and a gamer probably won't be very happy with a four-pipe card.
Actually,
PriceGrabber shows 6600s for the same money, so a X600P is currently overpriced at $110. I think 6600s also have very overclockable cores, which can help with newer games like Doom 3, Half-Life 2, and Far Cry.
BTW, the PCIe version of the 5900 (the PCX 5900) just sucks. It's clocked much lower than the AGP version, which is already at a disadvantage to comparably priced ATi and GF6 cards in newer games.
Edit: I'm talking in US dollars. $110 AU/CAN is pretty good, I guess, tho I still think the X600 series is too slow for gamers.