Any culture group that expresses itself through expensive clothes will find another expensive way to show group membership if clothes aren't an option. Other subcultures (think grunge, or tech people) either use cheap mismatched charity-shop styles or use other signals (e.g. running Linux at home).

This is so true! If the definition of fashion is extended to also include the latest smartphones, laptops, or service memberships. I never thought of it this way, but makes a lot of sense.