I agree with coachqueencoach, I would pass. It's hard to get the smell out..and also if the current owner couldnt get it out, you probably can't either.
Most smoke will air out (pot smoke, fire smoke etc.) but cigarette smoke STICKS to leather(and anything) and gets absorbed. I have done a lot of research because I purchased a beautiful bag and the cig. smoke is not just slight, but overwhelming. I opened it on my way home from the post office and out came the odor. I am now trying something suggested on another thread as my last resort.
If you have a leather that can have a leather cleaner applied, wiping it will help. But search the threads for smoke odor because we went through a great discussion on many ways to remove the odor and people have had a lot of success with the methods.
Wish you the best of luck in removing the odor. Awesome seller for disclosing the information to you. My seller did not and so when I opened it I gasped!