Yea I bought a few back in the day. Mainly in Real estate, but I was very familiar with the industry and usually had a good idea for BS and quality info.. This was before marketers transitioned to social media also, I would be really reluctant to do so now but would really have to investigate to make sure it was not BS or the person knew what they were doing. Barrier for entry to create a course seems sooo low now that its a big pool of BS.
But for most part I was very satisfied with courses I purchased, some paid off 100x and were well worth it. I used to have a criteria in mind but would be flexible if need be. Usually liked when I found someone who was knowledgeable but not the best marketer or hadnt scaled yet. Gave me ability to reach directly to creator and ask questions. Keep it under a certain price range. etc.