I am eagerly awaiting the day when some smart-arse economist comes up with a new clever “law” for what is so obviously going on — to wit, the way a middle-class couple’s combined income of well into six figures seems to disappear into thin air before either of them has bought even a tube of toothpaste.

The best I can come up with for this common and dismaying process is the law of reverse Rumpelstiltskin. So, far from turning our straw into gold, our healthy pay cheques vaporise in a puff of smoke, leaving us prowling Waitrose for food past its sell-by dates and popping into Oxfam to refresh our wardrobes (and yes, I have done both and I know lots of others who do the same).

When I look back on my childhood I realise that I never had it so good: holidays at home on my grandparents’ hill farm on Exmoor, vacations abroad — skiing, safari, you name it — and, best of all, we were looked after by a mother who did not work outside the home and who loved us. Oh yes, I forgot to mention: there were four of us and the sole breadwinner was my father, a civil servant/environmentalist/author, who somehow managed to educate all six — he later added two more — children privately on what I now realise was a shoestring.

As we know to our cost, you now have to be a hedge fund manager, an oligarch or a private equity magnate at the very least to be able to afford the lifestyle that my parents were able to supply me and my ingrate siblings with three decades ago. You have to be a banker at Goldman Sachs to have such a litter, let alone educate them all privately and give each princeling their own bedroom (the average house price nationwide has topped £200,000, but it is closer to £300,000 in London) or access to a second home.

You can’t even be just averagely rich or reasonably well off any longer to afford any of the above. A Halifax survey found that only nine professions could afford private school fees in London in 2005, compared with 19 in 2000. Oh, no: you have to be a have or a have-yacht.

Various figures have been put on how rich you have to be to be a have, to rank among the top 1% of the population in terms of wealth.

My rich neighbour on this page, Jeremy Clarkson, says you have to earn £250,000 just to be “comfortable” today. He was, frankly, being a little coy. The Times recently reckoned that in order to live the sort of lifestyle that my parents did back in the 1970s and into the 1980s — to live in houses that are only partially mortgaged, take regular foreign holidays and send their children to smart schools — you have earn upwards of half a million pounds a year.

As for being a have-yacht, that’s another ball game entirely, involving sickeningly obscene sums of money, multi-million-pound bonuses, taking the helicopter to the Daylesford farm shop to buy a parmesan wheel for your dinner party, dropping millions on a milestone birthday party in the south of France where your guests are serenaded by Robbie Williams, keeping a private jet with bespoke Versace interior and so on. The New York Times reckons that the haves’ annual income rests around the $1m (£513,000) mark, but the have-yachts’ annual income is between $4.5m and $20m a year.

So, feeling poor yet? I am. And so are all my middle-class mates, too. When I look around my normal, as in nonCity, contemporaries they are all working their socks off, hamster-wheeling, both the husband and the wife (only one in 10 women of working age can now afford the luxury of staying home unwaged to raise her children, according to the Office for National Statistics). They are raiding their parents’ nest eggs to keep their heads above water, remortgaging their houses to pay the school fees and, if they go abroad at all, they head off to eco-turismo communities in Sicily where several families share a swimming pool (if there is one) and all eat pasta together.

It is not hard to see why we church mice all feel sorry for ourselves. We may be well off by any historic standard, but it has never been so expensive being rich. And it’s all the fault of the haves and have-yachts. As the super-rich are getting richer all the time, they are driving up the prices of the things that we middle classes used to be able to afford on one income, but now can’t manage with two.

Let’s assume the middle-class family has a combined income of £100,000, which is £60,000 after tax. Then assume they have two children. School fees have risen by 45% since 1999. House prices: well, I needn’t go on. Art: just look at the splashy vulgarity that overtook Sotheby’s the other day. Family holidays: absurdly pricey and now guilt-making, too. Travel, council tax, healthcare, utility bills and services such as plumbers, cleaners and electricians are all subject to above-average inflation. Disposable income? Don’t make me laugh.

While the consumer price index inflation rate may be 2.7% and retail items such as CDs, DVDs, electronic equipment, imports from China and so on may be more affordable than ever, the inflation rate for the middle-class family (thank you Stephanie Flanders, of Newsnight, and Capital Economics for this figure) is closer to 7%. But it feels much higher.

There is only one upside to this, which is cold comfort to us middle-class whingers, I admit. It may be more expensive than ever to be rich, but it’s cheaper than ever to be poor. oI have two important questions of state after the publication of photographs of David Cameron with one of my aforementioned siblings last week.

One, where did they all have their lustrous hair cut en brosse like that and why didn’t I know about it when I was “up” with their lordships? I could have used a good bouffant do myself.

And two, forget the haircuts: how on earth could they afford those strange Jeremy Fisherish tailcoats at all, retailing at £1,000 a pop? To my certain knowledge, at least two of the pictured bucks’ only source of income was my old friend Max Grant — the maximum student grant available — a cheque that came via the kind offices of the Inner London Education Authority, abolished along with the Greater London Council by Margaret Thatcher’s government.

It is reassuring to think that back in the good old days the living expenses down to the white facings of the Bullingdon Club coats were kindly provided by Ken Livingstone, is it not? But how times have changed.

Here we are in 2007, 20 years on, with tuition fees and have-yachts, and the only chaps who can possibly afford the Buller today are not the sons of the English gentry or the privately educated products of middle-class, middle-income homes, but the sons of Russian oligarchs and hedge fund managers. I rest my case.

rachel.johnson@sunday-times.co.uk

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