At a certain wealth level, $900 is functionally the same as $9. I step over a penny, but to Bill Gates a $100 bill represents an even smaller fraction of his worth than $0.01 does to mine.
Not saying I'd buy this case if I were a billionaire, but if I liked it then cost isn't going to stop me.
You're right of course, but I think it misses the point, depending on your outlook.
For me, it's not about whether or not $900 is a lot of money. There's just something perverse about spending that amount of money on something which, intrinsically speaking, is not worth that valuation. There are better products for protecting your AirPods at a fraction of the cost. Hell, buy a second pair of AirPods! I couldn't, in good faith, throw that amount of money down the drain when there are so many good causes it could go to instead.
You could buy an overpriced, statement, protective case for, say, $200 - and give $700 to people who genuinely need it.
Don't mistake what I'm saying though. I'm not saying you should never buy anything expensive. A $930 AirPods case is nothing compared to a new car and I don't see any issue with people buying new cars! But I would see a moral problem with someone buying a Toyota Camry for $500,000 just because another 'high-end' brand had put their logo on it.
Hopefully one day you
will be a billionaire. But if I were you, even when money is no object, I'd still object to paying ridiculous sums of money to companies that, frankly, haven't done enough to earn it - and I say that as an Apple user!