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 :)
The area in which you are working is quite complex both in terms of describing inventions and in terms of the changing legal landscapes. An expert is definitely suggested. Even then, the terms of an agreement would be difficult to protect under patent law. This makes such a business model harder ...
You might want to try unbounce.com they have a free version that has their branding on it but allows for the use of most features and if its for a course then when they are done they can upgrade if they wanted to get rid of the branding. Just a thought take a look. Might be easier to setup then...
Very few brands will openly discuss how much they spend in advertising. This is a highly-sensitive data and a competitive advantage. You can use industry averages for cost of acquisitions, however. If you use $1 per click and/or $15 per client acquisition, for example, you can do simple math to ...