What is the value of Zhao Qidong in Xi 'an Painting Academy?

My brother is a member of China Calligraphy Association. His family has a pair of calligraphy, about 2m high and 1m wide. I think I bought it at 3000 in 2004. Considering your figure and the implication of the painting, I personally estimate that it will cost at least 8000- 15000 yuan! Because I've never seen a picture of this painting, it's just an estimate. Also, I want to point out that many people's paintings have collection value after him, so cherish them! !