So very rarely does it happen that someone thinks they have an exceptionally valuable book and it turns out to be true. A gentleman called about a book signed by Matisse. When he brought it in, I discovered he hadn’t mentioned it was also signed by James Joyce. 
It was a beautiful 1935 folio-sized edition of Ulysses with illustrations by Henri Matisse, the crown jewel of the Limited Editions Club catalogue. They printed many other nice books signed by their illustrators, but none with quite this much cachet. The man who had it was settling an estate, and inclined to accept a NY dealer’s offer of $10k. That dealer probably has a buyer willing to pay $15k or more. The only thing as rare as books that valuable are buyers for them. Well, it was fun to see, anyway.
An interesting contrast passed through our store the following week. It was an elephant folio, supersized 1975 Moby Dick illustrated and signed by Leroy Neiman, with a preface signed by Jacques Cousteau…which, for me, was all too much of not quite good enough things. It takes a lot to live up to Melville. And, with all due respect, the Cousteau signature was just a bit silly perhaps. It was a book that could be said to be worth a few hundred dollars, but I’d rather not be the one saying it.
Duttenhofer's Books 
Thanks so much for posting this. I really love to hear stories like this. You are so blessed to work someplace that you love and have such great knowledge of,,,(or is that ‘someplace that you love and a place of which you have great knowledge)?
A story worthy of the Antiques Roadshow! I love the 5 things to do when you think you have a ‘valuable’ book. #1. Stay calm. Though I’m not a book dealer (an avid collector!) I do know rare book collectors and dealers. I’ve learned that all doesn’t quite meet the eye when we stand with a friend in the attic and their husband (who is definitely not a book dealer or collector) finds a box of old books that once belonged to deceased Uncle Harry; the husband won’t let ANYONE touch, look at, or speak of the books because their so valuable (because they’re old, leather-bound and classics in the English language). ; ) Ten years later, the books are still in the cardboard box in the friend’s hall closet and the husband’s ‘million dollar books’ sadly inert and on their way to an uncertain future.