What is the auction transaction price of the dragon-handled phoenix-headed watering pot of Yue kiln celadon in Song Dynasty?

Yaozhou Kiln has a national treasure, which can be seen by anyone who has been to Shaanxi. This pot is very interesting. First, turn the pot upside down. Water is poured from the bottom of the pot. When it is full, turn the pot over. Water pours out of the spout, but the bottom can't flow out.

According to the porcelain catalogue of the Yuan Dynasty, the production process of watering pot is rather strange, and the firing needs to go through three processes, each of which is more complicated. After these three processes were fired, they were connected in turn, forming a well-structured Yuan Dynasty reflux tank. This kind of pot violates the traditional method of pouring water into the top of the pot. It turns the pot upside down, pours water into the pot from the bottom, puts it right and then pours it out, so it is called a reflux pot.

The watering pot was a kind of toy porcelain at that time. It was discovered in Shaanxi in 1970s, and now it is on display in Shaanxi Provincial Museum as a national treasure. In 2007, Sotheby's auctioned a Yaozhou kiln reflux pot for $660,000, which was very expensive.