It probably also depends on who you reach, too. In my case, they told me they wouldn't sell me any parts (e.g. replacement drivers), but would do all the necessary work that was required for $45.00 and they'd cover the shipping to get the headphones back to me. I think other people have indicated they've charged a flat fee of $30 or so to get a pair of headphones re-cabled. Either way you look at it, they're providing a service to keep their headphones going for a long time - regardless if they are past the warranty period, or not. Plus, they're not charging you an arm and a leg for the service - just a basic service fee. I guess that's what "quantity buying" gets you. I'm sure they're not paying a whole lot for their drivers - even on the higher-end models.
good point my friend, though buisness is buisness and they are obviously still making money from fixing cables drivers etc even with standard fees. I expect they love this thread what with all of the mishaps and broken hp's that they have to sort out. They will never send out seperate parts because we would all be making our own custom Grados from scratch. Rs1 drivers.. ps1000 housings.. probably don't cost that much.