But generally speaking, a class should be around 50 yuan.

As for how long it takes to learn, it depends on one's talent and hard work. Some people learn fast, while others learn slowly. Just like primary school study, there is a difference between good grades and poor grades taught by the same teacher. As the saying goes, the master leads the door, and practice depends on the individual. However, in general, if you are serious in class, it will be good to practice for one or two years after class.