The most positive aspect of the increasing rarity is that it triggers a search for alternatives to the vanishing great masters and leads to the acknowledgment of unduly neglected artists. Few have heard the name of Leo Gestel even though he was one of the best-known figures of Dutch avant-garde painting on the eve of World War I. His still life Gladiolen, signed and dated 1913, betrays a mix of influences, from Italian Futurism to the earlier French Fauvism. It sold at the June 24 Christie’s sale for £505,250 ($993,000), a world record for the artist but a very reasonable price for a picture of that splendor—avant-garde Dutch painting of the late 19th through mid-20th century remains vastly underrated, excepting that of artists who, like van Gogh and Piet Mondrian, left their homeland for France.

The Belgian Frits van den Berghe is another forgotten figure. In his remarkable Bloemen over de Stad, which also went on the block at Christie’s, the distant legacy of Fauvism may be detected in the palette, while some black outlines and the rendering of the plants and the houses point to the influence of German Expressionism. All this is blended in a beautiful picture, unlike any other painted around 1929 to 1930, when van den Berghe signed this gem. At   £241,250 ($474,000), the piece was a steal.

The relative underpricing of the subtler masterpieces of Impressionist and early 20th-century avant-garde painting may well continue until the last of these works finally leaves the market. The very few multimillionaire collectors who have been around for a long time are either deterred from buying by the overall price level or hold so much art already that they are rarely tempted to acquire more. And the ultrarich mostly hunt for obvious trophies in the areas into which the auction-house marketing teams shepherd them. It would make little sense for these marketers to encourage big money to take an interest in vanishing rarities.

"Rarity Rules" originally appeared in the September 2008 issue of Art+Auction. For a complete list of articles from this issue available on ARTINFO, see Art+Auction's September 2008 Table of Contents.