Oprah Winfrey has not sold a Gustav Klimt painting for $150 million or any other reported amount. It's possible that this transaction occurred after my understanding or that the information is inaccurate or speculative. Please note that financial details of private art sales may not always be publicly disclosed, so it can be challenging to provide precise information without up-to-date sources. I recommend referring to recent news or trusted sources for the most accurate and current information on this topic.