If biz class is $10k and economy is $1k, I'm taking economy even though I make enough money to afford $10k. I just can't justify it. Same with a hotel at $500/night vs. $1500/night...The former I can justify (barely), but the latter just seems insane. If I was a multi-millionaire than things would be different, but normal people luxury is good enough for normal people like me.
I've taken biz class before when it made sense (e.g. $1500 from Beijing to LA one way when economy cost $1000 for the same trip). I've also stayed in a $400/night pool villa in Bali (with a $900 round trip biz class ticket from Beijing via Hong Kong...but that was a steal, RIP Hong Kong Express Airlines), both worth it, both seemed really luxurious to me, I can't imagine doing more than that (though I guess with today's high inflation, it is inevitable that the $400 pool villa will cost $1000 soon).