Forget Cinderella carriages and castles. Keira Knightley's got the right idea As Sir Paul pointed out, when someone of your calibre chooses to go "cheap and cheerful," it does give other brides-to-be pause. Is any day, however "big," really worth £20,000 (the current going rate for a British wedding)? And that's before the emotional cost is calculated; when a bridezilla is intent on perfection, anything less is a catastrophe. "These costs have got out of hand and it is very sad if it puts people off marriage," says Sir Paul, who launched the Marriage Foundation last year, a charity that promotes a "mend it, don't end it" approach to long-term relationships. If people thought that they could not get married unless they had a glittering celebrity-style wedding, I think that's tragic. Moreover, if that 24 hours is freighted with such Disney Princess expectation, lord knows how any happy couple is going to cope with the everyday it's-your-turn-to-take-out-the-bins mundanity of married life. The whole more-is-more trend was kicked off by the Beckhams and their glorious be-throned, imperial purple tackfest in an Irish castle, back in 1999. Given Victoria's metamorphosis into a stick-thin, image-conscious fashionista, I have the distinct feeling that she would rather sit through every last dire performance of the doomed Spice Girls musical Viva Forever! than display those particular photos on the baby grand now. But at least Posh and Becks are still together, unlike Katie Price, whose preposterous Cinderella carriage wedding to Peter André did not result in a fairy‑tale ending. Tom Cruise and Katie Holmes memorably had a tiered wedding cake taller than the groom at Odescalchi Castle in Italy, but they never even made it to their seven-year itch. Elizabeth Hurley and Arun Nayar's extravagant 2007 ceremonies in Britain and Jodhpur may have made the cover of Hello!, but four years later their Goodbye took place in the divorce courts. Russell Brand and Katy Perry also held their 2010 wedding in India, with a theatrical procession of camels, elephants and horses to commemorate the event; 14 months later they split up. When Sir Paul McCartney married his second wife, Heather Mills, in 2002, the setting for their elaborate ceremony was a castle in Ireland. By glaring contrast, his third wedding, to Nancy Shevell, took place in 2011 at Marylebone town hall in London and was witnessed by just 30 guests. Those couples who care more about the venue than the vows should perhaps take inspiration from diva Mariah Carey, who renews her promises to her husband Nick Cannon as often as the rest of us renew our car insurance, most recently in a Cinderella gown at Disneyland. An annual ceremony would keep the bride busy and the groom on his toes, and with careful budgeting, the £20,000 could last for years. So, Keira, I commend your frugal elegance, your understated dignity. But just remember, if you decide in the future that you really wish you'd worn a frothy meringue, with a train of Swarovski crystals and pedigree Russian blue kittens draped around your neck (I know I do), you can always have a rerun in 2014. In fact, feel free to fly me over for a modest pastis at your family's £3 million French estate and we can start planning while the marquee is still up.