If you go to work now, you won't make any money. Now that the RMB has appreciated, you have earned more than half of what you did in previous years. The average monthly income is about 5000 to 7000 RMB. Of course, there are some exceptions, but the relationship between newcomers is not good. Because many Koreans have already worked in South China, it is still possible that they can't find jobs.
Visa fees are relatively cheap, classified as 400 yuan to 800 yuan, and the ticket price depends on where you started from and which institution you bought it from. Both Beijing and Shanghai are cheaper, and 800 yuan in the off-season is 2,000 yuan more expensive.
/This is the website of the Korean Embassy. There is a lot of helpful information on it. Take a look. Good luck!