If the Government were to set the minimum price for alcohol at $1.50 - a reasonable and workable price - it would mean a seven-standard-drink bottle of wine could not be sold for less than $10.50.
How does this compare with the price of alcohol at the moment? Well, you can buy cask wine for $0.74 a standard drink, Kristov Vodka for $0.81, Lindauer sparkling for $1.40, Stolichnya vodka for $1.50, and Chivas Regal for $2.05 a standard drink.
Contrary to some of the myths being spread by the alcohol industry and its friends, minimum pricing will not affect every alcoholic product - especially if you buy your alcoholat a bar. It will only affect those sold below the baseline price per standard drink.
For example, a 330ml bottle of Steinlager Pure retails for about $2.16. As it contains 1.3 standard drinks, the price of each unit of alcohol is about $1.67.
If a minimum price of $1.50 were to be introduced it would not affect the price of this beer, especially at a bar where you would be paying about $8 for one bottle.
Back to Mr Key: if you want to get the cheap and nasty stuff, it currently sells at pocket-money prices - less than a dollar per standard drink. However, lots of the nicer brands already cost $1.50, or more, per standard drink.
Right now, the cheap and nasty stuff is really only appealing because it's cheap. A minimum pricing scheme removes the price differential between good and poor quality products. Once it loses the cheap, it just becomes nasty.
So when Mr Key says introducing minimum pricing "could force people to drink poorer quality liquor instead of drinking less" he must be confused.
The Prime Minister's own science adviser, Sir Peter Gluckman, has consistently said that price is the No 1 factor that influences the availability and accessibility of alcohol.
So Mr Key knows price increases are very likely to reduce consumption. His science adviser has repeatedly said it in public, and his Government has shown increasing price reduces consumption by raising the price on tobacco and committing to further increases.
The purpose of increasing price is to reduce harm. The evidence shows this is the most effective way to do so.
Minimum pricing targets the products that are favoured by the people whose drinking causes the most concern - the heavy, harmful, and young drinkers. These are the people whose drinking can be fatal for themselves and others.
Recent debates have focused on heavy drinkers and how they are less responsive to changes in price.
While it's true heavy drinkers are less responsive to price than other drinkers, we shouldn't confuse less responsive with unresponsive.
Their consumption levels are so much greater to begin with that even a small decrease is likely to be significant particularly in the long term.
The Scottish Government worked out implementing a minimum price of 45 pence (87c) would reduce weekly alcohol consumption by an average of 3.5 per cent.
Now that might not sound like much and it's not if you are a moderate drinker.
By their calculations a moderate drinker would reduce his or her consumption by only about 4.8 drinks a year.
The decrease for harmful drinkers was over 278 drinks a year.
Plus it's not just the heavy drinkers we need to worry about. There are lots of people who may not be problem drinkers now but could be in the future.
Raising the price of alcohol isn't just about reducing the consumption of those who are already drinking heavily, but preventing people from becoming problem drinkers down the track.
Alcohol-related harm costs New Zealand $4.4 billion a year. Introducing a minimum price is one effective tool we could use to reduce this massive cost significantly.
