Value of Art

     I came upon something interesting online.  In this article a man has in his possession a physical Campbell's soup can that is autographed by Andy Warhol.  It is a rather interesting story of how he came to own the can.  Here is the article:

http://www.npr.org/2006/05/09/5391527/warhol-signed-soup-can-art-or-memento

     He wanted to sell it at auction, but finding a price for the item was difficult.  Some, like me, assumed that the can would be extremely valuable.  The auctioneer disagreed.  While the paintings of soup cans sell for tens of millions of dollars, this actual soup can would, or so the auctioneer thought, sell for the low five digits.  He said that since Warhol never presented the can as "art" it was not nearly as valuable as one of his paintings.  From what I can tell these autographed cans are rare, there might not be many of them in existence, far far fewer autographed cans that actual pictures that he painted.  So if they are technically rarer, why are they so essentially worthless since they are not technically art?  I would take the autographed can over one of the paintings any day, it is a much more interesting piece.  To me the object is more tangible. I wonder if this value difference points to the pretension and arbitrary nature of valuing contemporary art.