How much is Zhao Shuxin's calligraphy per square foot?

Teacher Zhao Shuxin took the initiative to write me a word. When promoting Mao calligraphy in Shaoshan, I checked it later. It is available online all over the world, and the collection price is more than 10000 yuan. These are not important, mainly because Mr. Zhao is highly respected and has made great contributions to the promotion of Mao calligraphy. Unlike other hype themselves.