You know, smelling used (or new!) books would be a good idea. I remember when I purchased Alan Moore's "Watchmen," my complaint was that, while the book was excellent, it smelled really bad. I don't know what it was--ink, glue, paper? Some combination? But man, it smelled terrible. My hardshell guitar case also had an awful smell when I bought it.

I guess the moral is that you should smell things before you buy them.