When is a comedy course actually worth paying for?

I keep seeing courses at wildly different prices, and the syllabus alone doesn’t really tell me whether the money buys anything I couldn’t get from writing and gigging more. What would make you think a paid course is genuinely worth it — detailed feedback, a small group, lots of stage time, a showcase, ongoing support, something else? And what would make you walk away even if the tutor looked good?