WIY,
Are you fabulously wealthy? If not, al tadin es chavercha ad shetagia limkokmo.
As others have pointed out, there is nothing inherently assur about buying expensive luxuries. Is it praiseworthy for someone, even if wealthy, to live a relatively simple life? Will it reduce jealousy, and possibly leave more money available for more important things? I would agree that the answer to these questions is “yes”.
I don’t think, though, that someone should be degraded or looked down upon for not acting with what is essentially a midas chassidus.