Had this discussion in work recently actually as rolling tobacco you can only buy in big packs now too. I came to the conclusion that your 'part time' smokers who only have <5 a day will more than likely quit as NRT is available for free so they'll probably take that up or move over to e-cigs. Anyone who smokes 6-14 a day might or might not quit, just depends on their individual views and situation and 15+'ers it won't affect i don't think.
So i think it will work for the ones who don't smoke much having to buy a big packet at a higher cost will no doubt make them think twice. But Baby
steps and all that. Pricing people out of a lethal habit is probably the most effective way of getting people to quit or not take it up in the first place