Gatekeeping is a complex job of managing boundaries that do not just define others but that also define ourselves. Status symbols — silk shells, designer shoes, luxury handbags — become keys to unlock these gates.
Pierre Bourdieu's "La Distinction" is a great text that investigates this topic in depth. It's (among other things) about taste. How it's inherited through generations, how it's a gatekeeping tool for jobs and status.
What you wear isn't the whole story btw. It's also how you wear it (as exemplified above ("Chavs" wearing Burberry)). One of Bourdieu's examples is art and how one speaks about it (using certain words, knowing the "right" works of art etc. Another example might be wine).
I don't know if Bourdieu is widely read in the US, but he certainly influenced my thinking about class, class boundaries, and taste. Highly recommended.