It’s conceptual art. The banana and the tape can be replaced as needed. Still, it’s hard to think collectors who paid $120,000 for the work will get anything like that if they sell it. One of the bananas was already eaten by a performance artist, who called the eating an art work.
The artist is Maurizio Cattelan, known for his gold toilet, his Pope attacked by a meteorite, and his kneeling Hitler doll.
I've heard that a lot of these art pieces are tax scams.
A collector buys an artwork for $100k. A few years later he donates it to a museum which appraises it at $10 million. So he paid $100k for a $10 million tax deduction.
Everyone along the way profits -- the artist, the collector, the museum, and the appraiser.