Where can I purchase 15 minutes of fame?

This entertaining and surprisingly instructive book should probably come with some sort of health warning like, "Art Dealing Can Seriously Damage Your Self-Esteem."

It is not, as American dealer Richard Polsky characterizes it, a career for the shy, the faint hearted, the easily offended or, frankly, the entirely balanced. Extreme highs and lows are built into the efforts of most dealers to make giant fortunes (since wealth is always the aim and sometimes the achievement) by acting as self-interested intermediaries between artists and collectors.

Richard Polsky's episodic and often funny narrative is woven into the chronology of his lengthy and frequently frustrated ambition to become the permanent owner - rather than just the buyer and seller - of a superior Andy Warhol painting. "Superior" is a significant qualifier, since Polsky is not only a Warhol enthusiast to the point of obsession, he is also fastidiously discriminating about what constitutes the artist's better - as well as his less good - works. He can also tell a genuine Warhol from a doubtfully authentic one, a finished from an abandoned one, even a good painting from a great one.

"A great painting affects you like a tattoo," he writes. "It penetrates every pore of your skin and is with you forever." This may not be the language of high aesthetics, but it serves.

Here Polsky, himself both dealer and collector, darting back and forth between the West and East coasts, looks at some of the auctioneers, dealers, and collectors he has known. His critical faculty, underpinned by a thorough knowledge of Warhol's life and art, stood him in excellent stead as a self-defense against the shenanigans of the artfully weaving and dodging dealers he encountered as he pursued his Warhol.

They are, by Polsky's account, a decidedly rum crew. Snobs and snubbers to a man. Incorrigible name-droppers (Polsky likes to do this, too, in his book). Difficult, mystifying, calculating, arrogant, insulting, amoral, and silly, they can also be wonderfully chummy and charming (some of them) when the mood strikes them (or when they sense they have an advantage, or an impending sale). They are a fascinating breed, and Polsky obviously enjoys knowing so many of them.

"I Bought Andy Warhol" acts, among other things, as a reminder that the world would be a much duller place if it didn't contain a good smattering of such daring oddballs and enterprising entrepreneurs. Without them, we would be culturally poorer - and so, financially, would quite a lot of artists.

As for these, Polsky has an ability to describe in very few words the essence, as he sees it, of the work of Pollock or Cornell or Johns. Here he is on Lichtenstein: "A painter who converted comic-book images into fine art by using their graphic format and Ben-day dots - the tiny dots of color that make up magazine and newspaper images - to transform a wide range of subjects." Accurate, certainly, but hardly eulogistic. In other words, he is concerned with the "what" rather than the "why" of art, and would make a good writer of short encyclopedia or sales catalogue entries.

Warhol is the honorable exception among the artists he describes. We learn a great deal about him. But it is the dealers who are subjected to the most detailed and amusing characterization. Polsky has a fund of anecdotes about them. The artists, after all, are basically interesting as manufacturers of commodities that can be turned into money, the raw material of the art trade rather than its creativity. Why would one need to know more about artists than the facts? Creativity in the dealer-world is the art of finance, not paint.

It is never quite clear whether Polsky himself is completely taken in by such a perversely upside-down view of art and its ideals. Probably not. But it is, in a way, hardly surprising that, of all artists, it is Warhol who is the hero of this book. He is, after all, the artist who turned commercial images into icons. The artist whose work explores the conviction that behind the surface of a painting lurks - nothing at all. The artist who painted dollar signs.

Polsky himself comes across as rather likable. If he didn't, this book might seem a rather more cynical exposé of the world he inhabits than it does. But he presents himself as a man who has a delicious way of putting his foot in it at the wrong moment and isn't afraid to laugh at himself (as well as at others) in print.

He is more embarrassed by his occasional faux pas and by his tendency to be taken for a ride by his canny or cruel brother dealers than he is eager to retaliate by flinging dirt at them. Only one dealer seems to have earned his out-and-out dislike. For the others, despite their faults, he shows a sneaking admiration.

The finale of the book is quite gripping. And it involves the alarming, brusque, teasing character of Vincent Fremont, responsible for the slow dispersal among collectors and collections of the Warhol works left in his estate.

Without giving anything away, Fremont turns out, at the last minute, to have an appealingly mischievous - and decent - streak. Or at least he has a very perceptive understanding of Richard Polsky's burning desire to buy a superior Andy Warhol and the excitement involved.

• Christopher Andreae writes about fine art for the Monitor from Glasgow, Scotland.