Formal training takes 12 months, which is about 1000 every year, and it will be thousands in a few years. The low fees only attract others to practice bodybuilding: for example, WTF Taekwondo only teaches some low-energy courses like leg press, as well as basic footwork, hand knives and many other things. Although it costs 50 yuan for half a year, it's useless. I only attend classes twice a week. What can you learn? The key is to ask clearly when applying for study, and don't be cheated.
Also, Sanda is divided into off-stage Sanda and on-stage Sanda. If you want to defend yourself, you should learn from Sanda under the stage. Some things are not taught on the stage, and they can't be used on the stage because of the rules, but Sanda under the stage is suitable for resisting bad people.