Don't make fun of the $120,000 banana – it's in on the joke | Jonathan Jones

Before we get to the banana, we should consider where it was eaten. Art Basel in Miami Beach is a franchise of a famous Swiss art fair that takes place far from the Alps, in sunny Florida – presumably because it’s too cold to sell art in Basel at this time of year. This surreal displacement adds to the sense that contemporary art, like haute couture, is a luxury for people with more money than sense, who can afford to follow their favourite art dealers around the planet like migrating birds.

Enter Comedian. That is the title of the artwork by Maurizio Cattelan, renowned for his stolen gold toilet, that has taken this sophisticated trade fair out of in-crowdy art websites and into mainstream news. Cattelan’s Comedian is a banana taped to a wall. Descriptions tend to carefully specify that it is fixed there with grey duct tape. Everyone stresses this somewhat bare technical fact, as if to find physical evidence that it really is, after all, art. At the weekend, after Comedian had already sold for $120,000, an artist named David Datuna joined the queue of fair-goers eager to take selfies with Comedian, but instead peeled back the grey duct tape, removed the banana from the wall and ate it. The piece was remade but then removed from the show, presumably to prevent further stunts. No such luck – a graffitist with few artistic pretensions wrote “Epstien (sic) didn’t kill himself” in the blank space it left.

No one has yet accused Cattelan of hiring Datuna to eat his art – though he was suspected by some people of arranging the theft of his plumbed-in gold toilet from Blenheim Palace earlier this year. But there’s a curious similarity to these artworks and their fates. To point out the obvious, gold and bananas may be very different in market value, but they’re both yellow. America, as Cattelan called his loo, reduced gold from the precious to the base as it invited users to pee and poo on this most coveted of metals. A banana is another way of making the point: that we’re all organisms that eat, excrete and die. (After eating an overripe banana, Datuna may well have needed the loo.) Cattelan’s toilet mocked the money-obsessed art world by being potentially more valuable for its raw material than its concept – reflecting a market that can turn shit to gold. His banana makes the same joke the other way round by being glaringly not worth its asking price.

As Damien Hirst has said, art dealers are unpleasant people (to paraphrase) who “sell shit to fools”. Cattelan has been putting the same thing more wittily for years. Parisian dealer Emmanuel Perrotin, who unveiled Comedian at his Art Basel Miami booth and then had to deal with its destruction (by, well, getting another banana) knows being mocked is all part of representing him. In 1995, Cattelan got Perrotin to dress as a giant phallic rabbit.

Cattelan is acting out the tragicomedy of the contemporary artist. When Marcel Duchamp chose “readymades” such as a urinal or snow shovel, no one thought they had financial value – most were thrown away without a thought. Today’s museum versions were recreated long after the fact, when Duchamp became a hero to the conceptual art movement in the 1960s.

Nowadays, art can’t get away from money. That’s all anyone wants to know about it, and dada gestures are part of the capitalist miracle. Lo, this banana is worth $120,000 because … well, just because. It’s the idea that is valuable, not the banana, insists the Perrotin gallery. Are you so stupid that you can’t see that? Every satire – including someone eating the banana – becomes another bit of added value.

Cattelan is a philosopher like his hero Duchamp. He doesn’t think he can bring down the art market. Instead, the mordant works he conceives as a semi-retired joker suggest a deep melancholy. He’s the clown who has to go on clowning when he knows his jokes don’t do any good. Comedian is of course Cattelan’s self-portrait. But he’s not happy in his slapstick skin.

Why can’t anyone just tape a banana to a wall and claim to own a Cattelan for free? Then again, who would want to? A banana stuck to a wall with grey duct tape just looks crap. Only an idiot would decorate their house with this.

It’s more than a century since Duchamp’s Fountain, yet the equivalent of putting a urinal in a gallery can still cause a global sensation. Comedian is a new low and a new high, as contemptuous a comment on the art market as it’s possible to dream up. The man who dressed his own gallerist as a giant cock has in effect told art collectors they are morons, and got paid for the privilege. Having made his latest world-weary gag, he sits sadly in his dressing room looking at his clown makeup while Datuna eats the banana to become the new king of comedy.