There is no end to learning the sea, and there is no conclusion on the extent to which you become a "calligrapher".
In ancient times, some people became famous in their twenties, and some people were unknown after practicing all their lives. But this does not mean that unknown people have poor calligraphy skills.
The price of calligraphy works depends not only on the level of calligraphy, but also on many secular influences, that is, the dependent price increase.
Judging from the way you ask questions, find a local teacher to take you from the beginning and see the talents and opportunities.