To be honest, if he is really never ever going to fly again, he's going to save tens of thousands of dollars over his remaining lifespan so I don't really grok why paying 9K this time would make any difference in his lifestyle.
Do you know what the phrase "I've been a long-time troll" means? I think you do, but maybe the other people responding to this wind-up don't...It's creative though, I tip my hat to you for creativity. You seldom see a good troll that people swallow that easily these days...
If there is any fact behind the troll, and you actually do need an upgrade, for pity's sake, why don't you call the airline and ask them the procedure and the costs? Don't you have to inform them anyway about the oxygen tanks or you just planning to sorta spring it on them at the gate?