Earlier quoted context omitted.
Luxury implies comfort or quality.
Quality is not necessary for a good to be a luxury good. Only for demand to go up disproportionately with increases in income. Practically this means luxury goods are purchased to convey status. Consider Range Rover or Jaguar, which are known for being low quality but luxury brands. Premium is the word that means paying extra for an increase in quality. Consider a Toyota vs a Kia. These things are often correlated bu…
Okay, if we want to limit ourselves to economics jargon rather than vernacular.
>Practically this means luxury goods are purchased to convey status
No, practically it means poor people aren't buying them much. Only some luxury good purchasing is related to status signaling.
>Premium is the word that means paying extra for an increase in quality
I'm not aware of a context where that would be the standard definition, though in some contexts it may be the excess portion of the price.