Who sold a lot on Clickbank or JVzoo? Any advice you recommend to get started with a new course on those platforms?

Give Vimeo a try.

Cost of customer acquisition will depend a lot on what type of course you're looking to sell and your target audience. No one will be able to give you a straight up answer here. If you're able to provide more details, I could give some more nuanced advice :)

This is my wheelhouse but unfortunately I am heads down putting the final touches on my MastermindTalks event. If this hasn't been answered in the next 2 or 3 weeks, I will come back in to reply... Good luck!

There are merits to both options, but unless your economics dictate one over the other, the choice should be made by your consumers. I would suggest that you use landing pages to test both pricing models and let the relative click-through-rates tell you which is the right way to go. Validate the consumer preferred model before you commit to it. You may discover one as a clear winner overall, or that one wins out in a key market segment. You may also find that the distribution is fairly even. Keep in mind that it is possible to utilize both - think Amazon selling audio books, but also offering Audible Subscriptions. Ultimately, you'll want to make sure that the economics work for you - and focus on maximizing customer LTV (life time value - ie the total you'll earn per customer over the lifetime of that customer). I'm happy to explain the process of testing these (even before the product exists) in detail. Just shoot me a message.

Just be frank and flexible. Say: 1. We don't have that stuff. As a startup with customers that love customized solutions, we've tried to be nimble. 2. But I can see that your organization needs a streamlined process. We can deliver. 3. This stuff isn't for us internally. But show us some examples of what you'd like to receive, let us know how it's used, and we'll produce whatever is needed. In other words, treat your big marketing partner as a client. Bring a white board, listen, and produce!