1. Market demand: If the market demand of Zhou Keren's calligraphy works is not high, then the price of the works will be limited.
2. Quality of works: If the quality of Zhou Keren's calligraphy works is not high enough, or is not recognized enough, then the price of the works will also be affected.
3. Economic conditions: The economic conditions of the market will also affect the selling price of artworks. If the market economy is depressed, people's purchasing power will drop, and the price of works of art will also drop.
4. Competition: If there are many similar calligraphy works on the market, the price of Zhou Keren's calligraphy works will also be affected.