One of the key ways in which politicians demonstrate that they are another species of human being entirely is in their obsession with what are euphemistically called “Major Events”. Today there was another outbreak of Major Eventitis in relation to the 2014 G20 meeting, to be held in Brisbane, a decision that infuriated NSW politicians.

Maybe it’s because politicians never have to endure the inordinate disruption that such events cause to the rest of the population.

The G20 has degenerated into a pointless talkfest more quickly than most fora. The degeneration usually begins when the founding leaders depart the scene, which might account for what’s happened with the G20, which initially featured George W. Bush at the shambolic end of his presidency, Kevin Rudd, Gordon Brown and Nicolas Sarkozy, of whom only Sarkozy stuck around for a while.

Julia Gillard has, predictably, been accused of bias and political calculation in the selection of Brisbane, although she could have put it anywhere and been accused of trying to curry favour with voters of the relevant city. There’s nowhere where Labor doesn’t need a massive lift.

Major Events come with major price tags, of course. The 2007 APEC meeting in Sydney, where John Howard and Alexander Downer belatedly discovered a purpose for a multilateral forum they’d ignored for most of their time in government, was initially forecast to cost $216 million. Predictably, the cost blew out — particularly for security, which ended up costing $170 million by itself.

“The direct costs of hosting APEC 2007 will be offset by the significant benefits attached to being the host economy,” Alexander Downer assured us at the time. When then-deputy premier of NSW John Watkins dared to express scepticism on this point, Downer, in what was hardly the finest hour of his then-press secretary the unfortunate Chris Kenny, declared “the fact is that trade with APEC economies generates around $70 billion annually for his state”.

Indeed, though quite what that fact had to do with the massive disruption occasioned by the APEC meeting, including snipers on roofs and other security theatre overkill (all hilariously mocked in The Chaser’s finest hour), wasn’t clear.

According to the Prime Minister’s statement today, the G20 meeting is currently forecast to cost $370 million dollars from the Commonwealth, plus some spare change from Campbell Newman. Yes, you read that correctly — hosting the meeting will cost more than a third of a billion dollars. On previous form, that cost will blow out.

And while politicians like Downer and Gillard are shy about saying exactly what the economic benefits of such meetings are, the cost enables us to have a guess at some figures. To offset the cost to taxpayers, the estimated 7000 G20 attendees would have to spend about $53,000 each during their brief stay in Brisbane. Viewed as a stimulus measure, it notionally amounts to a transfer of $300 million-odd from the rest of Australia to Queensland. But based on the APEC spending breakdown, much of the money will simply be spent within government — additional funding to ASIO, Attorney-General’s, the AFP and Defence, for example, for security.

The biggest amount of funding will most likely go to the Department of Prime Minister and Cabinet, and be spent on additional staff for that department and capital on ICT equipment and fitting out venues. IT and comms contractors will probably be the biggest winners, but Queenslanders shouldn’t count on much of a windfall from the event – a great deal of the money will never leave Canberra.

And then there’s the now-standard abrogation of civil liberties that accompanies all officially-designated major events. Remember Morris Iemma’s “anti-annoyance” proposal for World Youth Day, and his draconian “restricted area” laws for APEC? The curtailment of protest rights in Perth for CHOGM? These big gatherings come with big crackdowns on basic rights to free speech.

Politicians might love them, but the most sensible attitude of people outside Brisbane ought to be: you’re welcome to the G20.