Despite the price being 3,300 won, I think it is a very informative lecture. It was enough to learn the basics of JSP, and everyone said that the sound was low, but even though it is a bit low, it is not unheard if you turn up the sound. It is just plain audible. However, if you have something like KakaoTalk notifications turned on... you might be a bit startled by the sudden loud sound. Anyway, I will watch the JSP lecture and go.