Fair enough, though in my opinion there's less than a 1% chance that you'll be able to just go out and get replacement cards from Apple or a third party. I think you're going to have to take the unit in for service for such a fix. You may be able to find cards on ebay or similar sources, but they'll be scarce.
even then, that wouldn't be so bad.. I'm 4 stops from the w.vilage store and the nmp looks like I can just put it in a backpack and go get it fixed.. if it's under warranty, maybe they'll just switch out the entire unit.. I'm ok with that.
the problem arises with non warrantied units.. if they can put in a new gpu and send me on my way, that's cool. if they expect me to drop off the computer and pick it up next week, that's not cool.. if they expect me to buy a new computer, that's not cool either.
to me, it's both easier for them and easier for me
if they just sell the part I need and that's that. (and this is a point where to conversation starts splitting. in my mind, it makes more sense from all angles for apple to just sell the part.. but apparently, there's something apple has to gain in this scenario by not selling that part to me. what will they gain? I'm not going to walk out of there with a new computer at that point.. I simply won't and I truly believe most other people wouldn't.. so why wouldn't they sell me a part?)