I was allowed to use my educational discount on components ...
Let me start by saying that I have a great local Apple store that values customer loyalty and serves me well.
I took my G5 in for service and it literally blew up in the store. Turns out it had a leaky radiator, the fluid got on the mother board and Boom.
They owed me nothing. I was well out of warranty. I told them that.
But, they insisted, and I mean insisted that they replace the machine so I now have a 2.66 Quad.
I wanted to upgrade the hard drive to 1TB which is what I had in my original, wanted to upgrade the video card, and a few other things.
I got my educational discount on all of the upgrades.
I like to think that they treated me well because I have treated them well the many times I have been in.
So, in answer to your question, I think there may be some discretion they can exercise when they find a case "compelling".
In my many years of being a Mac person, my experience is that Apple goes more than the extra mile to do the right thing. That's why I'm so loyal.
sjh