The county set thinks Dicky and Daffy Tottering are absolutely topping. A well-to-do Surrey farmer took her pair of pet sheep to the preview of the eccentric couple's selling exhibition in London's Mayfair - and Sir Angus Ogilvy was guest of honour at its opening.

Dicky and Daffy, as readers of Country Life will know, are cartoon strip characters - ageing huntin', shootin' aristocrats whose ability to cope with the modern world depends largely on the resourceful Mrs Shagpile, their only remaining servant, and regular injections of gin and tonic. Typical gag, from Dicky: "The barbarians are at the gates... I've just found Freddy playing computer croquet".

At the smart O'Shea Gallery's exhibition, the colourful original artwork by 37 year old Annie Tempest is selling for pounds 425 per framed strip - double the going rate for newspaper editorial-page cartoons. Her specially drawn single images are pounds 295-pounds 550 framed.

But it is not just the high prices that make Dicky and Daffy a publishing phenomenon. It is their merchandising. Green wellie types, who would never be seen dead in a product-name T-shirt, are being offered 12 up-market Tottering tie-ins. No other cartoonist for adults has made such a hit with manufacturers.

The face of a British-made Corniche-style 11-jewel carriage clock, commissioned by Halcyon Days - the London suppliers of objets d'art - sports a hand- drawn portrait of Dicky and Daffy clinking champagne glasses at a picnic. It costs pounds 645. Halcyon Days are also selling an enamel box with hand-drawn Totterings, pounds 125. There are mugs (pounds 12), ashtrays (pounds 25), teapots (pounds 35) and a tie with Tottering crest by Thomas Pink (pounds 29.50). At pounds 150 a pair - Tottering crested velvet slippers by Henry Maxwell, sponsor of Tempest's book Tottering-by-Gently: limited edition of 500, pounds 30 each.

Expensive though Tempest's original drawings may sound, they are pocket money compared with the pounds 9,500 being asked by the London gallerist Chris Beetles for Ralph Steadman's original pen and ink cover for Punch, commemorating the magazine's 150th anniversary.

As prices for living cartoonists go, Tempest is sole trader in a middle market of her own, patronised less by cartoon connoisseurs than by well- wellied countryfolk eager to validate their lifestyle. Above her: Beetles. Below her: Jack Duncan's cartoon and book gallery in Museum Street, Bloomsbury, where I bought Willie Rushton's 1991 Private Eye cartoon of Jilly Cooper for pounds 45.

Tempest had had qualms about O'Shea's bullish prices for her work, but was consoled when I explained how the cartoon market is constructed. "I suppose, then," she said, "that I'm the Old Rectory, Beetles is the stately home and Duncan, er, the stable block?"

Duncan's is the fun end of the market (guffawing at Scarfe or Steadman's surreal satire at Beetles' is a gaffe of H M Batemanesque proportions). The ebullient Duncan - a writer in the Sixties for the BBC's pioneer satirical show That Was the Week That Was, and the man who made Les Dawson famous on Yorkshire television - holds bibulous monthly openings of newspaper cartoon exhibitions and stocks work by more than a dozen cartoonists. Editorial-page cartoons by Chris Riddell are about pounds 250 framed; gags by Ed McLachlan such as his wildlife vigilantes liberating pots of live yoghurt from a supermarket, pounds 100.

You can still telephone newspaper and magazine cartoonists to offer to buy their work. But Rushton (another That Was the Week veteran) and Riddell now sell theirs exclusively through Duncan. Rushton told me: "I'd rather somebody else handled the selling side. Jack can deal with problems and ask for more money. It's worth that extra percentage".

But just because a London gallery has begun adopting Grub Street cartoonists does not mean they are going up in the world. Duncan pockets a modest 35 per cent commission (50 per cent is the norm). And the cartoonists themselves are showing symptoms of identity crisis, being unsure whether or not they should be coming out of the closet - which is where most collectors hang their work.

Duncan's robust opinion is that there are not enough cartoons in closets. "Let's not be pretentious about cartoons," he says. "I'm not trying to glamorise them, nor trying to pretend they haven't been paid for once already by newspapers. That's why I ask artists to keep their prices low. The public's not daft.

"But an original by a really brilliant cartoonist knocks spots off your average wishy-washy watercolour of a garden gate - and it's a fraction of the price."

At the Beetles stately home, the artists are dignified by the title "illustrator", rather than "cartoonist". If you are thinking of investing, the safest bet is the increasing value of the work of his "big three": Ralph Steadman, Gerald Scarfe - and Ronald Searle, the GOM of cartoon illustration, to whom both Steadman and Scarfe are stylistically indebted. Prices, says Beetles, have doubled in five years. His current big annual exhibition, showing the work of 75 artists, took pounds 150,000 even before it opened.

Nostalgia is potent in this market. Never mind if Scarfe's and Steadman's barbs remind you of Gilray - the correct market comparison is with E H Shepard, whose whimsical drawings of Winnie the Pooh fetch up to pounds 15,000 at auction.

Beetles can be sure of getting pounds 5,000 for a major Scarfe or Steadman, pounds 2,000-3,000 for a Searle - especially a St Trinians or a Molesworth. At a London auction house such as Christie's South Kensington or Phillips you might pay half those sums for such treasures - if you are lucky. Searle is avidly collected in America, where he used to live, and in Germany, where his prices have hit pounds 10,000.

You, too, should dig deep but be discriminating. Cartoons of faded celebrities enacting forgotten stories are the market's turkeys. The fact that at Phillips in March four framed cartoons by leading newspaper cartoonists Jon and Cummings, showing the trade unionist Clive Jenkins, failed to sell even at the measly estimate of pounds 70-pounds 100, is a warning. Duncan slashes the prices of cartoons unsold after six months. There's no news like old news.

`Tottering-by-Gently' in Mayfair, O'Shea Gallery until 23 December (9.30am- 6pm, Saturdays 9.30am-1pm),120 Mount Street, London W1 (0171-351 3321). The Illustrators at the Chris Beetles gallery, Monday-Saturday (10am-5.30pm) until 25 January. Jack Duncan Cartoons and Books,,10am-6pm, Saturdays 11am-5pm), 44 Museum Street, London WC1 (0171-242 5335).

Pictures: Willie Rushton's 1991 `Private Eye' cartoon of Jilly Cooper. Inset: Annie Tempest's lucrative creations `Dicky and Daffy'.