If you work in a Gucci or Louis Vuitton store, would you treat some customers different if they wore clothes from Walmart?

Of course not. But I would mention prices to the customer, like "These blouses just arrived. They're fourteen hundred and up." The customer is then free to leave. But each and every customer I served would receive professional courteous service not matter how he/she was dressed.

I live right across the bridge form Palm Beach and the ultra rich don't "go shopping" in the way you and I do. They send a member of their household or personal staff to the store for them. Or shop by appointment. They aren't strolling up and down Worth Avenue going from shop to shop.