Technically it costs bandwidth and electricity I suppose to make information available...

Not suing people for repairing or tinkering with your hardware is also a "cost" I suppose if you want to phrase it that way, because of the lost revenue you would have gotten from locking down the market and only providing overpriced replacements yourself. It's a cost in the same way that a law against stealing purses imposes a "non-zero cost" on all of us, since we don't have that potential source of revenue available to us anymore...

How so? Apple already has detailed schematics, repair shops have been getting them through shady FTP servers for years - making them accessible at this point is the cost of putting them up for download. Hell, ANYBODY making consumer electronics has detailed schematics or at least the gerber file for the PCB.

Components? Sure, but you bake that into the cost you sell them at. You're already buying them in massive quantities, so let repair shops order some from you - nobody is going to complain about having to pay x% over cost of materials to cover your expenses.