I have a purple clay teapot made by Zhou Guizhen, which was given to me by a work partner when my father was in Yixing in 2000. One pot, six cups, six cups.

I can’t see a picture of your purple clay teapot here. Zhou Guizhen’s models are either round or square. There are round styles like you said, but because there are more large-scale production costs in the later period, so The details still need to be seen by experts. Like yours, you just have a collection certificate, but you still need expert appraisal. If the collection is correct, it is a high-quality product. The price is usually around 100,000 to 200,000 when sold privately, and the price at auction is around 300,000 to 500,000.