American artist Richard Prince first rose to fame in the 1980s with a series of now famous images entitled 'Cowboys'. An image from that series sold in January this year for a record $3.4m making Prince the highest paid photographer in the world. But these cowboy images weren't even originals, they were pictures taken of the Marlboro Man adverts. The recently image sold is one step further removed - it's an image of an image of an image. This does, at least, illustrate the high regard in which he is held. But it also raises questions about the value of original art. This question ties in with a theme that reappears throughout his photographs, sculptures and paintings, visible in the 30 years' worth of work displayed here - namely our voracious appetite for consuming things.