There is evidence to indicate this point. In 2011, a teapot be Gu Zingzhou was auctioned for over 17 millions RMB. This teapot was made by a grandmaster of teapot. Not only that, there was a Chinese painting engraved on it by an equally famous artist of the time, Wu Hufan. Because the teapot represented two great master's works, it became a highly contested item during an auction and the final bid settled at over 17 millions.
Here is a square teapot made in the 20th century by a renown potter Wu Yaoting. You can see a Chinese painting beautifully engraved on one of its side.
It is through a teapot (as it is passed down to the next generation), these features of art and calligraphy can be preserved. As a result, the cultural aspects of a teapot is far more greater in value than how much it is worth in the market.