re: scarcity, hirst and his dealer bought back works from saatchi when he was dumping them (er, deaccessioning) to prevent the market from flooding and prices dropping. and who bought that platinum skull? damien hirst (a consortium bought it, and he was a member of the consortium.) i think hirst lost much of his 'reputation' when he went fresh to auction with new works -- meaning he fell out of favor with specucollectors because they couldn't buy from the gallery and make profit on the way to, and at, auction themselves. 

hirst and koons might say that their art is the economy & is the zeitgeist.

volume also works:  koons, murakami, hirst, weiwei (and of course warhol) all create art by factory, and are argueably the most successful? richest? best-known? artists. (and fwiw, i have no problem with artists using teams to manifest their vision.)
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