Does art depreciate over time?

Looking at Art:

A drawing by Albrecht Durer, the very famous German artist who was born in 1471, was bought at an estate sale for $30. Once authenticated, it is now expected to sell for millions. Van Gogh often exchanged art for enough money to buy food during his lifetime, yet in 1990, a portrait of his sold for 82.5 million.  What makes these works so valuable? Is the artist’s fame the commodity being sold? What happens to the value of art when it comes to the work of artists who do not achieve great fame? 

Work in the Studio:

Although this question, about what happens to the art over time, is on my mind as I age, it does not stop me from creating more work. The challenge of making good art seems to be independent of all other worries. The painting shown here is part of a series of paintings about my feelings as we are all caught in a world with this virus without end.

Not Again, Watercolor, 12” x 9”