[gamblor956]

No one seems to have an answer for what model Apple can use

Every support contract of this nature that I've seen is a fixed, flat fee. And someone, businesses outside of tech, with their far higher costs, are able to make it work.

Apple could easily use this business model, but its profits would be far lower. Apple's grown quite large and comfortable with a business model centered around illegal profits (in this context, referring to the excess profits derived from their anti-competitive behavior) and like other businesses premised on abusive behavior, it's going to fight.