The facts of the case are this:
Ms Winfrey entered a shop, and checked out a bag. The clerk there told her that it would be "too expensive for her". Given that the clerk didn't recognize her, and thus only had her first impressions to go on (that of a dressed-down, African-American woman), there are only very few conclusions we can draw about her behaviour. One is that she definitely was guilty of classism, since she had no way of evaluating the affluence of the prospective customer, and so went with her first impressions.
Now, this is bad customer service no matter how you look at it. Whether or not a white woman in a similar situation would be treated differently is doubtful, if we're talking just about classism.
However, under the circumstances, we do have to add racism into the mix as well. This is arguably harder to substantiate. It would fit into the picture, however.
What you need to realize, Lorric, is that racism comes.in many forms, from the idiot in the street yelling at the Asians to the store clerk who refuses service to someone just based on how the customer looks.
This everyday racism is absolutely pervasive in our society. You will see it everywhere, if you look, but you, as a presumably white male, will never be a victim of it.
It does not surprise me that you have difficulty seeing this. We already discussed similar issues in the "Tropes vs Women" thread, where you were similarly unaware of the actual issue at play.
For your sake, please read up on the issue. I just know that, when you read this, you will feel bound to post a response. Please take your time with it. Do not once again post something right off the top of your head.