Almost anyone living outside London knows that when you pop to the city for work or pleasure, you're likely to pay a few per cent more for meals, hotels and everyday items than you will elsewhere across the UK.
Even so, those of us working in family law have found our eyes watering at the size of a number divorce settlements awarded by London's courts in recent years, payouts which have earned it the status of 'the world's divorce capital'.
The tag has been justified by examples such as the £48 million paid by leading insurance broker Jon Charman to his ex-wife Beverley, and the £100 million handed over by Russian tycoon Boris Berezhovsky to former spouse, Galina.
In some ways, the headlines generated by those cases and others have become a self-fulfilling prophecy. More wives in so-called 'international marriages' - and not just those who count themselves among the jet-set - have chosen to divorce in the UK because of an anticipated boost to their finances.
The effect has, not surprisingly, produced a response from husbands too, eager to protect as much of their assets as they can.
The result has been something of a divorce 'race' with increasing numbers of spouses vying to begin proceedings first in countries where they believe they might get the sort of settlement which is in their favour. British men, it seems, are more likely than ever before to file for divorce overseas than risk having to make a large settlement in English courts.
Even if the process is not clear cut, couples can spend time, energy and money arguing about the jurisdiction in which their separation should take place.
One of the factors underlying the increase in these cases that myself and my colleagues have detected is the impact of our increasingly international existence. In previous generations, where working and living abroad was more of an exception than a norm, couples shared a single nationality.
Now, as improved travel and communications have granted us greater professional and personal fluidity, relationships between partners from different countries are commonplace. So too is the appreciation of disparities in divorce settlements, particularly in marriages which might be in difficulty.
The value of such cross-border legal differences can be significant. Whilst British courts can award ex-wives maintenance for life, many other countries are considered less favourable to non-working and less wealthy spouses, for example limiting post-marital support to only three years.
The 'race' to be the first to initiate divorces has been most noticeable in European countries where a 'first past the post' system operates. In those states, divorces are usually heard in the country where the papers are first issued.
Of course, to issue divorce proceedings in a different country means justifying why you're able to do so. However, because there is now such a large number of people living and working abroad, a growing proportion of individuals qualify.
The "forum shopping" issue is one which the European Union has taken fairly recent steps to address. EU Justice Commissioner, Viviane Reding, announced regulations to dictate where cases should be heard if couples couldn't agree.
She added that the move aimed to end "the financial and emotional disaster" such a 'race' caused. It was prompted, in part, by statistics showing that 13% of the one million divorces across Europe in 2007 involved spouses from different countries.
The Commissioner's step was a noble gesture but only 10 of the EU's 27 countries have adopted the regulations, which are due to come into force in June next year.
Britain is among those nations not to have signed up because, among other reasons, of differences between its legal culture and those of other EU states.
The fact is that while couples still have a choice about where to have their divorce, it is hard to see how the issue can be effectively addressed. That means that more substance is likely to be added to London's divorce court reputation in the foreseeable future.