I was wondering if I bought a bare-bones Mac Pro with the 7300GT as the video card if I could upgrade it to the ATI x1900 later on from a 3rd party? I mean, could I buy one from NewEgg, where I can get it cheaper, or do I HAVE to go through Apple and pay through the nose to get it? If so, why? Isn't it the same card? I can get an x1900 XT for around $270 at NewEgg, instead of the $400 at Apple. If I have to buy it from Apple, that's not much of a choice.