As a buyer, I would do what you did. My experience has been that some time in a sealed container with activated charcoal or baking soda will remove most odor.
You may be a little hard on the seller though. Back in the day when many people smoked, it was common to have an adult beverage and a favorite tobacco product while stamping. The seller may not be the smoker. It may just have been that he got the stock from a smoker.
I have come across/acquired stamps and covers that smelled like they came from a tobacconist.
With increased sensitivity to smoke and other odors a seller should probably be aware that such odors will offend some buyers.
When I sell/donate/give away a stamp or cover, they always spend some time "in the box" just to be sure. When you handle material long enough you can get used to the smells and not notice it.
Dan
