Costs of smoking

The lead item on TV3 cited the Ministry of Health's bogus $1.9 billion figure on smoking costs. Hon. Tariana Turia continues to stand by her anti-smoking unit's $1.9 billion estimate of the costs of smoking to Vote.Health but, in correspondence, provides this teaser:

While giving a good indication of what the current costs are of treating the health damage caused by smoking, this figure has never been portrayed as a measure of what might be saved if compared to a world where smoking had been eradicated.

Is she ceding the point that smokers, if they didn't die of smoking related diseases, would go on to die of some other costly disease instead? If a cost can't be avoided even in a counterfactual world where smoking doesn't exist, can we really call it a cost of smoking? How can they continue pushing this number with a straight face?

Hon. Turia's letter:
Turia Letter 12 October 2010