From all psychology signaling is most powerful when it shows expensive resources spent on unpractical, useless things. As the peacock tail.

Spending a hundred bucks on something useful is not a signal showing wealth; but lighting a cigar with a hundred dollar bill is such a signal.

Being seen with, say, an expensive computer is less powerful wealth signal than being seen with an exactly equally expensive ring; the computer might be (even if it isn't) practical, but the ring states "hey, I can afford to waste money, so if you don't then obviously I'm of a higher social status/pecking order than you".