The problem with people who stink - and I would put most smokers in that category - is that they don't know they stink.
The same could be said for radicals not knowing how radical they really are, but I'll stick to the topic at hand.
I don't care if someone smokes on their patio but I don't want a piece of used gear to smell like smoke, and frankly I'm not sure a smoker is fully capable of discerning whether or not there is any odor on the amp/DAC/whatever it is. I have returned gear for exactly that reason in the past, thankfully the seller was honorable but it could have gone otherwise.