I thought luxury was being used by marketers as their favorite new mouth-noise that sounds good but doesn't mean anythingm Like "premium". If you pay $150 for a $1.5 bottle of wine it actually means overpriced but it is used to make it sound posh. Snark aside it could be "quality enough that it sells above commodity prices" but it is still about what others are willing to pay.
Luxury has many uses as a euphemism "No Karen, just because it is an apartment doesn't mean it will cause a flood of criminals!" NIMBY defense, "Sounds good so you will pay more." and the hillariously low bar to pass "Literally anything above neccessities to sell the place."
NIMBYs define "luxury" very broadly as a semantic tool in their warchest. There isn't a good definition of it at all, but it's commonly used to mean "high rents", or simply, market rate rents.
