it's a case of shall i buy drugs or have a smoke ?
... but try not smoking and see how the urge to have a smoke feels.
I have quit cold turkey before and that urge is really strong. Ozzie Osbourne told Howard Stern that quitting smoking cigs was way harder than quitting H or coke, etc.. Even when I quit using patches and gum/lozenges, that urge to smoke a cig was still strong...especially when having an alcoholic beverage or smoking weed, etc..
BUT I think I could cut down a lot if it came down to buying drugs or cigs. I know I'd have to have a cig for when I lose my temper, after sex, after a good shot of dope, etc..
I'm with MoeMentim though, buy tobacco and roll your own cigs. I know folks that do it and they say it's about half as much as buying cigs. They can roll 20 cigs for about $2-3 instead of buying a pack of cigs for $5-6. They've also come a long way on the machines that roll them for you so you don't have to take forever rolling it like a joint every single time you want a cig.