Imagine a museum where everything is for sale - that's the European Art Fair

• Visitors chat in front of a the painting known as 'Les Deux Femmes'

It is easy to dismiss these figures as irrelevant to the real economy, but unlike the bankers' imaginary money which has got us into such trouble, in art dealing real cash changes hands. There are no derivatives and a work of art is its own future.

(Sub-prime art is another story.) Almost 70 per cent of that global total is traded in the United States and the UK (that means London) and part of the boom was a big rise in sales of contemporary art. The peak in 2006-7 was the height of the bonus boom. New money likes new art, but that market has crashed by 60 per cent.

These figures come from the International Art Market 2007-9, a statistical survey published by TEFAF (The European Fine Art Foundation.) A co- operative of international dealers, it also organises the European Fine Art Fair.

The world's biggest and most important art fair, it is held in Maastricht. About 260 top dealers gather to display their best stock. One veteran observer reckoned that altogether there was a billion dollars' worth of art on show. The qualifications for entry are stiff and every separate item has to qualify.

A panel of 168 experts in 26 specialised fields vets the exhibits. No dealers are allowed in that day and quite a few come back to find embarrassing gaps in their stands. If you buy anything at Maastricht, you can be confident that it is the real thing and confidence is the basis of any successful economy.

The fair runs for ten days. It costs 55 (50) to get in. Nevertheless last year there were 68,000 visitors. The International Art Market Report produces a lovely acronym, HNWI. It sounds like a strain of flu, but it stands for "High Net Worth Individual", or people with liquid assets of $1 million (about 650,000) or more.

They are the target. At the private view, TEFAF entertained 8,000 people to a lavish drinks party. Apart from the paupers of the press like me, you weren't there unless there was good reason to think you were an HNWI.

SO what's it like, apart from the 25,000 roses and as many tulips that adorn the stands? Imagine a museum where everything is for sale; that is the standard and museum directors come to TEFAF to buy. There are antiquities – you could buy a full-size Greco-Roman marble Apollo, for instance.

There is furniture. One of the stars is a draped golden bed in the Empire style that belonged to the great French political survivor Talleyrand. At the other end of the historical scale is a battered sideboard designed by le Corbusier for Chandigarh in India. There is fabulous jewellery, but the highest value is in the art and there is a lot of it. The putative star of the show is a Gauguin of two Tahitian women with London dealer Dickinson. Painted at the very end of his life, it has a price tag of about 18m. It's a silly price. Poor Gauguin had clearly lost it. It is a rotten picture and there were many better things on sale.

Among the early Renaissance works was a little panel by Giovanni di Paolo. Dutch painting is well represented and I am always seduced by those low-key landscapes from the early 17th century. Dutch painters turned to paint sea and sky and light and weather and nothing else, and that was where modern art began.

There are quite a few on offer, but best was a lovely seascape by Simon de Vlieger, more than halfway to Whistler but painted in the 1620s. Whistler himself is represented by both prints and drawings. Also among the many prints, you could buy Rembrandt's etched masterpiece The Three Crosses for 1.5m, or a complete set of Goya's Disasters of War for 145,000.

Modern art includes several wonderful Matisse drawings, a lot of late Picasso, including a charming girl in a tam-o'-shanter. German and Austrian art is strong, including several works by Paul Klee, gorgeously sexy Klimt drawings, fiercely strange pictures by Egon Schiele, George Grosz and Otto Dix, and beautiful paintings by Alexei Jawlensky, Ernst Ludwig Kirchner and Emile Nolde.

The Impressionists are not so good. You could buy a Renoir that once belonged to Greta Garbo, but it didn't have much else going for it. More modest, but more beautiful are two lovely oil sketches by Seurat and intriguing early works by Van Gogh and by Mondrian.

THE Van Gogh at Galerie Frans Jacobs is priced 3.4m, but prices are generally not up front. Dealers deal; it's a game of poker and it's best to conceal your hand. Nevertheless, indicative prices are usually forthcoming if you ask.

Inquiring about a lovely Albert Marquet painting, I had to seek clarification as the price was "only" 265,000, not in millions like everything else. Then I searched for something I might actually afford. The nearest I got was an undistinguished, unframed print for 1,500.

Contemporary art consists mostly of modern masters like Josef Albers, Rothko, Willem de Kooning, or painters like Pierre Soulages from a postwar European generation that is making a comeback. Apart from Damien Hirst – represented by a pickled pig sliced in half selling for a grotesque $12m at Haunch of Venison – there were no heroes of the YBA scene and no-one from the current sub-prime Turner Prize coterie. Next most overpriced after Hirst was a mere scribble by Josef Beuys for 85,000.

There was a small Scottish angle. Two self-portraits in a silly pose at Marlborough were a rare opportunity to see recent work by Stephen Conroy. The Fine Art Society has a Mackintosh chair, a beautiful watercolour by Margaret McDonald Mackintosh and Wilkie's working sketch for his great Penny Wedding. It should be in the National Gallery, but at 200,000 there seems little chance of that.

Two works by Dr John Murray, Scottish pioneer of photography in India, are a rarity, though the prices of $25,000 and $30,000 (from an American dealer) are eye-watering. Also of Scottish interest is a magnificent painting of an Arab with his horse. Dated 1698, it is by Johann Georg de Hamilton, son of James Hamilton, an expatriate Scottish artist.

The Art Market report speaks of "distressed sellers" and your heart goes out HNWIs down to their last million. I don't know if that would include the Earl of Wemyss, nor can anyone guess what burdens his estate must bear after the death of his father last year, but it was sad to see three paintings from the Wemyss collection at Gosford House consigned for sale with Dickinson.

They are Poussin's Baptism, Jan de Bray's David Dancing Before the Ark and the Drunkenness of Noah by Bernardo Cavallino, and their combined value should not fall far short of the Botticelli sold to the National Gallery a few years ago. That a historic Scottish collection is being dispersed is the sort of thing you learn at Maastricht, which is also the biggest networking opportunity in the art trade.

Until 21 March, www.tefaf.com