It is a good thing if it means he has taken a leaf out of his predecessor Don Brash's book of frugality. There are signs Mr Banks is taking cheaper options where available, rather than claiming the maximum the system allows.
Banks' portfolios do not necessitate much travelling and his expenses indicate he is yet to adopt the practice of travelling round the provinces to attend the openings of the proverbial envelope.
However, it would be a bad thing if he was another minister such as Foreign Minister Murray McCully or Trade Minister Tim Groser.
It has been two years since the revolution sweeping through the Beehive in the wake of embarrassing revelations of misuse of credit cards and tortuous attempts to get around the rules resulted in a far more transparent system for ministers' spending.
Those releases are intended to both force ministers to think twice about their spending and to allow public scrutiny that ensures it is appropriate.
They are, admittedly, not primarily aimed at allowing us to see ministers' dirty laundry aired in public, as happened literally with Defence Minister Jonathan Coleman's underwear this week courtesy of a detailed receipt from a hotel laundry service.
But in general, after the initial flurry of activity when the spending figures of ministers were released for the first time, the releases have prompted less and less attention.
This is partly because spending trends have become clear - we know some MPs will have higher bills than others, especially those who live in far flung electorates.
We know ministers who have our international interests in their tender care travel more and entertain more - in fact, as Prime Minister John Key said, it would be of more concern if McCully was in the country than if he was not.
So ministers like McCully and Groser get some licence for their overseas spending, primarily because of the fear that New Zealand already comes across as the poor country mouse in international fora and a failure to shout a round or two or turning up to meetings in a crumpled shirt would only compound that.
McCully in particular knows New Zealand is a small country and the best way to be heard is through the subtle art of schmoozing. The best weapon in the schmoozing arsenal is a couple of nice bottles of wine offered up for the betterment of the nation.
But that does not mean we should neglect scrutinising the spending.
In general, the latest round of expenses showed the credit cards were being used in the manner they were intended - for work-related expenses.
It showed Ministerial Services has upped its game after the scolding it got from the Auditor-General over its lax monitoring of the credit cards.
That body responsible for policing the use of the cards now demands full receipts, queries items of expenditure and contacts overseas hotels to request copies of receipts if the original was not handed over.
It was also encouraging to see the staff responsible for those credit cards checking with Ministerial Services before spending on some items and feeling the need to justify even small items of expenditure. When Coleman's office was questioned about some relatively small unexplained items on a hotel receipt, the staffer said it was a minibar charge for bottled water and soft drinks. They then felt obliged to explain why bottled water was needed: "It was hot in Melbourne."
But there are already signs that the maximum limits on spending for certain items in the guidelines that come with the cards - such as the $100 cap on farewell gifts for staff - is now the default spend rather than the upper end.
The spending of MPs who aren't ministers remains largely inscrutable because Parliamentary Services is still immune from the Official Information Act, meaning we know what they spend, but not what they spend it on. That is less egregious than if the same cloak of darkness lay over ministerial expenses, because normal MPs do not get things like credit cards. It does mean ministers are subjected to a much higher level of scrutiny, however.
Those ministers will be gratified to know that the main reaction to a story about their overseas hotel and entertaining bills this week was in defence of them. Many likened the expenses to those of a company chief executive.
The entire point of the overhaul of the credit card system was to hold ministers to the same standards as company executives rather than be able to use their cards at will - and as time goes on it is sometimes forgotten that that was not always the case.
The reaction indicates the system is finally at the point where it should always have been.
