The guard was "warning" us that the items would be expensive by giving us a gentle heads up that we should be prepared for sticker shock. The point is that we didn't hear him "warn" any whites that the coats were expensive. They didn't need a "warning" because they don't have to worry about what they can afford, but I should. For some reason, when white people respond to this essay, this example is always the one that "confuses" them. I wonder why.