When politicians invoke “commercial in confidence” you have to wonder what they’re really trying to hide.

More likely than not, it’s their embarrassment at being taken for a ride. Well, that’s my theory.

I’m thinking of the special sort of embarrassment you feel when you’re wondering if you might have just bought a pig in a poke.

The special sort of embarrassment that just gets worse when some helpful friend confirms your fears with a look of disbelief and the question, “you paid how much for that?”, with the emphasis on “how”.

Take last week’s Queensland Government announcement it had paid the National Rugby League to move the first State of Origin match to Townsville.

How much exactly? Can’t tell you. It’s commercial in confidence.

But don’t worry, Premier Annastacia Palaszczuk assured us, “this is value for money”.

Treasurer Cameron Dick portrayed the government’s investment as part of an economic development strategy.

“Northern Australia has never – let alone northern Queensland – has ever seen a sporting event of this kind,” he said.

“We think every dollar we’ve spent has been well spent to support regional Queensland to support the economy of the north.”

He claimed the investment couldn’t be underestimated in terms of the value it would bring to north Queensland.

That’s nonsense. It could actually be estimated quite easily. Queensland Treasury is full of boffins with all sorts of economic models to work these things out.

How else, for instance does a government make the decision it would be a good idea to bid for a Commonwealth Games, or even an Olympic Games?

In the absence of any guidance from Treasury and unconstrained by any commercial-in-confidence considerations, here are my exceedingly rough calculations on whether the state’s investment in a Townsville State of Origin game makes sense.

First, although the Premier and her Treasurer were coy about how much the NRL managed to shake out of the state, southern sources put the figure at an unchallenged $8 million.

Second, visitors to Townsville last year spent an average of $647 a day, according to Tourism and Events Queensland data.

Third, let’s assume every visitor to Townsville for the game stays for two days. That’s $1,294 per head

That means, around 6,200 out-of-towners – or more than 20 per cent of Townsville’s Queensland Country Bank Stadium capacity – have to show up for the government just to break even on its $8 million investment.

I’ve got no idea whether that’s likely but even if the government covers its investment, is it a smart use of public money?

Spending $8 million of taxpayers’ cash to attract $8 million in tourist spending barely seems worth the effort.

And more to the point, did the government really need to spend $8 million to get the NRL to move the game to Townsville, after the latest Melbourne COVID-19 outbreak ruled out the MCG?

Even the NRL’s biosecurity experts apparently advised that tropical Queensland carried the least infection risk.

I know I’m making the mistake here of pretending that economic development – rather than a raw appeal to local voters – lay behind the Palaszczuk Government’s underwriting of the Townsville State of Origin game.

But still, even when our politicians are blatantly pork barrelling, can’t they at least pretend to be high-minded, beyond saying “trust us, you’re getting value for money”.

In any event, it’s a low-risk gamble for the government, especially if Queensland wins on the night.

Who’s going to remember, or care, how much the state paid the NRL for the privilege?

Who’d be the party pooper to say that was $8 million badly spent?

Actually, now that I think about it, I might have to rethink my original thesis: that politicians hide behind the commercial-in-confidence defence to avoid the embarrassment of having to admit they were taken to cleaners.

To be embarrassed you first have to have some capacity for shame and when it comes to using public money to win votes, politicians are shameless.