Prices are on a course-by-course basis. There are both free courses and paid courses on this site. The free course's videos are publicly available on YouTube, but by using the courses website here, you'll also get access to extra tips, tricks, and optional quizzes to help lock in what you're learning.
Paid courses are non-publicly available videos. Generally, these courses go more in depth than anything in the free courses and target more niche requirements (for example, a free course may teach the Svelte fundamentals, but a paid Svelte course may teach Sveltekit and help you build something with Sveltekit). It may be a good idea to view the free courses as pre-requisites for the paid courses -- of course, you can skip the free course if you already have the skills taught within!
Paid courses are priced independently. Paying for one course will grant you a license for only that course. Licenses will be emailed to you, then, you may create an account to redeem the license for this course. This also allows you to purchase a license for someone else -- simply buy the course and give the redemption code to the other individual.
If you're on the fence about a paid course, I recommend signing up for a free course and trying things out. This will give you an idea of the quality of the content, the course platform, and the quizzes. At this time, I do not offer free previews of paid courses -- use the free courses for that!