This reminds me of "The Darwin Economy" by Robert S. Frank (https://www.goodreads.com/book/show/12035503-the-darwin-econ...) where he proposes a tax on super expensive luxury consumption precisely because its main utility is social signalling. For example, spending $6 million on a sweet 16 party would have exactly the same utility as spending $3 million and paying $3 million in taxes on it, if everyone had to do the same. Probably more useful as a thought experiment than workable policy, but interesting to consider.