Frieze 2008: Money talks

Gavin Turk in his studio in east London Photograph: Christian Sinibaldi/Guardian

'If artists are primarily motivated by profit, they may not be artists any more," says Turk. 'They could just be producers of something' Photograph: Christian Sinibaldi/Guardian

Turk: 'If a piece has no price, is it good value? If the work is free, is it art?' Photograph: Christian Sinibaldi/Guardian

Isaac Julien by one of his lightbox works at the Victoria Miro gallery in London Photograph: Felix Clay/Guardian

'Warhol's use of repetition had real intellectual meaning,' says Isaac Julien. 'Nowadays, I wonder if seriality is not just a way of printing money' Photograph: Felix Clay/Guardian

Francis Upritchard working on a sculpture Photograph: Christian Sinibaldi/Guardian

'I lived in a squat for six years,' says Francis Upritchard. 'If I had to downgrade my studio, it wouldn't matter' Photograph: Christian Sinibaldi/Guardian

Upritchard: 'I’m sure it’s good to get the work out of the sun, but art needs to be used. It needs a thinking gaze. That is what makes it art, rather than just stuff' Photograph: Christian Sinibaldi/Guardian

Idris Khan in his Islington studio Photograph: Graeme Robertson/Guardian

Khan: 'It is difficult to take money as an artist. That's why we need galleries - a good gallery allows you to have a free mind' Photograph: Graeme Robertson/Guardian

Khan: 'You don't want your art to be treated like a commodity. I don't understand that throwaway attitude' Photograph: Graeme Robertson/Guardian

Susan Hiller installing a recent show in Berlin Photograph: Rainer Jensen/EPA

Hiller: 'No one visited Louise Bourgeois's studio until she was in her 60s' Photograph: Rainer Jensen/EPA

Jeremy Deller in Manchester Photograph: Christopher Thomond/Guardian

Jeremy Deller on speculators: 'Their investment life of risks and gambles makes the world more dangerous for everyone' Photograph: Christopher Thomond/Guardian