With all the talk of the value of Old Master paintings as a hedge against inflation because their worth has been proven, the Economist offers a compelling lesson in the vagaries of art market valuations with the story of the just sold Domenichino that achieved £9.2m at Christie’s:

The long history of Domenichino’s “Saint John” offers a salutary lesson in the vagaries of the art market—and of taste. In the 18th century, this picture was one of the most expensive on record. In the midst of the Napoleonic wars it was taken to London, where it was sold to Richard Hart Davis, a member of Parliament.

In 1884 it was put up for sale by his grandson, and bought in at a bid of 700 guineas. In 1899 the next generation tried again to sell it, once more without success; on that occasion it was bought in at 100 guineas. Subsequently, it was sold to Colnaghi, a firm that now belongs to Mr Bernheimer. Colnaghi paid just 70 guineas for the work. In the century since, the price has risen 100,000 times. But it may never each that height again.

Opportunity Knocks (Economist.com)