Art is Long and Lime is Fleeting

Published in the collection The Lives of Harry Lime - novelization of episode 15 of the radio program of the same name as the collection.
Passing himself off as a dealer in rare art, Harry Lime buys a painting for a small amount convinced he can sell it as a Renoir for a far greater amount. His plan is interrupted by the arrival of Paul Bazin, a man Lime had conned in the past.