What would be an expression for:
Someone who wants expensive stuff; someone who wants luxuries, and who lacks in appreciation.
Consider social climber
A person who is eager to gain a higher social status. Also called climber. [Oxford Dictionaries Online]
Related terms are arriviste, nouveau-riche, parvenu, upstart which generally mean
a person who has suddenly risen to a higher economic status but has not gained social acceptance of others in that class [The Free Dictionary.com]
A person who acts in an affected manner in order to impress others. [Oxford Dictionaries Online]
I think you are referring to a social climber:
- One who strives for acceptance in fashionable society.
Also a material person can convey the idea:
- Of or concerned with the physical as distinct from the intellectual or spiritual: "Great men are they who see that spiritual is stronger than any material force, that thoughts rule the world" (Ralph Waldo Emerson).
Source : www.thefreedictionary.com
This may be a controversial choice, but I might use affluenzal in this situation. This would be the adjective form of the relatively new term for pathological materialism, affluenza.
This term officially denotes a real disorder, but its practical connotation often seems to be 'the condition of being spoiled as hell.'
Since influenzal is the adjective form of influenza (one of affluenza's etymological parents), affluenzal would logically follow as the adjective form of affluenza.