How much is a flat foot of Liu Yuming's calligraphy works?

Liu Yuming, male, was born in 193 1, Taian, Shandong. Researcher. Second-class painter of Chuanfu Painting and Calligraphy Institute, senior researcher of Jiangdu Painting and Calligraphy Institute and senior academician of Zhongyuan Painting and Calligraphy Institute. Honorary director of the Art Committee of Jinling Printing Society and international member of Hong Kong World Famous Artists Association. Honorary senior academician of New Shenzhou Painting Academy, specially invited senior painter. I loved calligraphy and seal cutting since I was a child and insisted on self-study for more than 50 years. I first copied Gu Shuhua, and later I learned from Qi Baishi, Xu Beihong, Wang Xuetao and other masters, which benefited me a lot. After retirement, I concentrated on Chinese painting and seal cutting.