I'm sorry, but I'll say the opposite based on my opinion and experience.
It is true that you will find all the information on the internet. But buying a course is not just for information. Information alone will NOT help you achieve your objectives RAPIDLY. Self-learning is not easy, you must be determined and self-disciplined. You will make many mistakes that you could avoid if someone is guiding you.
When you buy a course from someone, you are NOT just buying the information. You are also buying connections. Depending on the course and the credibility of the seller selling the course, you will get more benefits than you paid.
I have purchased courses online, if the course I bought is BAD or if the vendor does not provide assistance, I request a refund. Take note that I walk away from the courses WITHOUT money back guarantee.
For the good courses that I bought, I really appreciate them. I have been well advised, I have been part of your private group and you will really feel that you are being guided.
They will also introduce you to other people who will help you succeed faster; Get that first customer and make that first dollar.
The writing is important. It is what drives sales. Sales pages are all drafting works. The only drawback is that you must be passionate about writing. If you are not passionate about writing, look for another interest.
There are many online writing courses. Just search on Google and use your judgment if they meet your expectations and remember, always go for those who give 30 days money back guarantee.