If I walked into the same store and the associate said, "Come here, don't tell the manager this but I'm going to let you know of a sweet deal just for you today on this item. No one else knows about this," then I would be inclined to furrow my forehead and pretend like someone was calling my phone so I could leave.
My wife and I have learned that the special treatment, often under the table, heavily persuades us to not buy a product. We have walked away from apartments and car dealerships because of the sweet deal "just for us," when "no one else is supposed to know about it."
I really believe the most comfortable sell is the one open to everyone. And there has to be transparency in company hierarchy, from top to bottom. If not, it just feels like your buying into something that feels at best, vaguely slimy.