I don't think those 50+ titles have PhysX content that would make a dedicated PhysX unit such as 8800 GS sweat. 96 NVIDIA SPs is still a huge amount of rated shader compute power. 192 bit memory bus doesn't matter, the card isn't transferring large chunks of data (such a textures), it's just crunching lots of math in real-time. To look at it that way, if a PhysX title does have physics load that makes a dedicated 8800 GS sweat, a single GTX 280 machine is in for a significant graphics performance hit.
If he isn't getting a 8800 GS for less than $40 bucks, 9800 GT is cool.
Gadgets, Phones, Tablets, Cameras, TVs, HiFi...NextPowerUp