How high do you think the price of a pack of cigarettes has to go before only rich people smoke?

I live not far from NYC, and in the city, a pack of cigarettes is $15. Despite that, people still smoke. A recent news piece on smokers taking their smoking breaks outside office buildings referred to them as “the last holdouts.” I find it amazing that people will pay $15 for a pack of cigarettes. New York State has high cigarette taxes yet that does not stop poor people from buying. At $15, if someone smokes one pack per day that comes to about $450 per month.

How much will people pay for cigarettes before they decide that the price is high enough to quit? At what point will the price be so high that only rich people will be smokers?