I'd like to know how "ghetto" people can afford to smoke with how much a pack of cigarettes costs. $12 for a pack of 25 is pretty steep.
As for a typology of people who smoke and why some people continue to smoke, IMO, it's highly individualized and has nothing to do with class, status, income, educational attainment, gender, or any other variable you attempt to throw in the mix. People who continue to smoke despite the fact that society views it as reprehensible, may do so based on physiological differences. The same as how some people are alcoholics. For some people, it's not that easy to simply stop. And for people like me, who are fully cognizant of the detrimental effects of smoking on the body, they still engage in that highly self-destructive activity regardless. I'm not stupid. Smoking is terrible.
I find it interesting how many 'kinds' of people continue to smoke. From medical doctors to technicians to artists and graphic designers to academics. Every kind of job I have worked in has its smokers. There are still lots of smokers out there from every walk of life.