Is her bump really worth £1.6 million?

You can ' t blame an ageing actress these days for taking a fourth or even a fifth husband: it is the least she can do to help celebrity magazines locked in an increasingly brutal circulation war. With OK! and Hello! sharply down in the last six-monthly sales figures, only an endless supply of A-list engagements, weddings and christenings can, it seems, deliver the readers who would otherwise drift to Now and Heat. But with exclusive photo spreads now typically costing proprietors six- or even seven-figure sums, do huge "buy-ins" - such as the recent Liza Minnelli and Joan Collins weddings - really make financial sense?

It is a question being asked in publishers' finance departments this week as bids reach £1.6 million for exclusive access to Liz Hurley before and after she gives birth next month. An auction began the moment magazine editors discovered that Hurley, 36, was expecting a baby in April. The Evening Standard understands that Hello!, which initially expected bidding to end at £800,000, stopped at £600,000, before OK! offered a million more - though if Hurley makes a financial settlement with former lover Steve Bing's lawyers any such magazine deal could be invalidated. Bing's lawyers have denied any negotiations with Hurley.

"It's a big sum, but even at that price it would be worthwhile," says a Hello! source involved in the negotiations. "It would be syndicated across the world. You don't get an opportunity like this very often nowadays, as a lot of the top celebrities are too embarrassed to do these magazines."

It is typical of the deals that Richard Desmond, the proprietor, is now aggressively pursuing for OK!, as he wields his chequebook to rebuild the quarter of its circulation lost in the past year. According to the Audit Bureau of Circulations, six-monthly sales have fallen from 598,000 last year to 487,000 today - and just 326,000 of them at full price. Hello! has also seen a sharp fall, from 843,000 to 527,000 - although its figures balance out over the full year. The winners have been the cheekier newcomers: Heat has doubled to 356,000, and Now has risen to more than 550,000.

Richard Desmond's response has been to pour in cash. Over the past two months, his rivals estimate that he has spent £1.5

million buying in celebrity exclusives and advertising them on television. Joan Collins's wedding cost him £380,000, Liza Minnelli's around £500,000, - even the engagement of Hear'Say singer Kym Marsh to EastEnders actor Jack Ryder cost an estimated £250,000. Sources at the magazine suggest that the Joan Collins wedding special sold 60 per cent more copies than usual, although part of that is attributed to the Heat-lookalike, Hot Stars, which now comes free with each issue. A figure of 750,000 is confidently predicted for this week's Minnelli issue.

"The sums sound a lot, but the deals pay off handsomely," says a former OK! insider familiar with the figures. "Richard Desmond isn't doing it just to boost his ego - he knows his business, and only spends if it makes financial sense. Every time he's spent, it has generally worked out." There have been occasional disappointments - Tracy Shaw's wedding last June, estimated to have cost him £350,000, failed to sell - but, normally, large sums are recouped by syndicating photographs. They are also widely used across Richard Desmond's newspapers, and if possible repackaged: the Beckham-Adams wedding photos, bought for £1 million in July 1999, were used across three issues of OK! and in a subsequent book.

"He could earn back half the cost of the Liza Minnelli wedding just by syndicating photos to American magazines such as People," the source explains. "The same goes for Liz Hurley's baby. That would be used across two or three issues, and could boost circulation to 700,000 or 800,000, which brings up the average in the important six-monthly ABC figures."

OK! also competes to win the second-serial rights to celebrity photographs its editors spot in other British magazines, even while they are still on the newsstands. Last May, a Geri Halliwell picture spread in the UK edition of Marie Claire prompted an auction over second-use rights. According to a source involved in the negotiations, OK! offered £50,000 to run the photographs, whereas Hello! dropped out at £40,000. Both magazines also bid for Victoria Beckham pictures in last October's Marie Claire - again, with OK! winning the rights for between £5,000 and £10,000 per photograph, even though the Outside Organisation, Victoria Beckham's publicists, only released selected images. Naturally, Express Newspapers - proprietor: Richard Desmond - was part of the deal. "Under the terms, the cover of Marie Claire had to be shown in both cases," the source said. "So it was also good PR for Marie Claire. He didn't mind."

Rival editors blanch at the sums involved. "We'd spend £10,000 to £15,000 on a set of pictures we really want," says Mark Frith at Heat; Jane Ennis at Now would go up to "tens of thousands". At Hello!, editor Phil Hall doubts whether the numbers add up for OK!, especially with the cost of television adverts that ran throughout February. "If you're spending £1 million to achieve 100,000 extra copies, it's shoot-yourself-in-the-foot stuff," he says.

But he acknowledges that the right faces can boost sales considerably. In January, Hello! paid a reported £300,000 to cover the wedding of Westlife's Bryan McFadden and Kerry Katona. "Our Westlife issue was up 25 to 30 per cent," Hall says. He has even greater expectations for this week's issue, which contains pictures of an "ordained" Robbie Williams marrying his two best friends. "We paid over £100,000, as he's the largest star in Britain. We have great expectations for the Robbie Williams issue."

But these days Hello! - which once paid the Duchess of York a reported £1.2 million - is not bidding against OK! for the bigger deals. Some observers believe that money is short, and that the Spanish proprietor, Eduardo Sanchez Junco, is taking an unusually close interest in minor financial decisions.

Phil Hall insists: "Things are tight if we're talking about buying up third-rate celebrities, but not for the A-list. If I'm spending a large sum of money, I'll obviously speak with the proprietor. We're still in the fight if it's worth having."