The added value of an A-list owner

As many collectors grow increasingly risk-averse, works previously in the possession of respected, trusted or famous owners are in demand.At Frieze Masters, the star piece on Dickinsons Surrealism stand is Ren Magrittes LEmpire des lumires (1949). The works previous owners include the late billionaire collector and former US vice-president Nelson Rockefellera factor that contributes to its $25m price tag. Also on the gallerys stand is Yves Tanguys Sans Titre (1935, 1.2m), which was once owned b