What is the current calligraphy market like? Is there room for development? What are the prospects?

Difficult. Calligraphy is a lifetime thing. That's what the so-called old books mean. When Qi Baishi first arrived in Beijing, no one cared about calligraphy and painting. If he hadn't closed his doors for ten years and started a new road, he wouldn't have caused a sensation in the world. Moreover, most of the calligraphy market is now valuable and has no market. So if you want to make money, you'd better choose another job.