Bob, the seller, shows the geology and mining-focused book, apparently printed in 1546, to an impressed "Old Man" Harrison and Chumlee. He claims that it once sat on a shelf in Newton's library, the proof being the bookplate (i.e., an individual's sign of ownership) on the inside cover and the doggy-eared pages the physicist was well known for. Though written in Latin — not a language just anyone can read these days — Old Man posits the book should be worth quite a bit if Newton really did own it, and so he calls in an expert to verify the claim.
The expert's assessment: the book was actually printed in 1546 (written by a famous alchemist of the time to boot), and the reference number above the bookplate indicates that it was indeed Newton's. However, the binding was redone sometime in the 1700s, devaluing what the book would have otherwise been worth. Even so, he appraises it at $20,000, which shocked Bob.
The seller starts at $15,000 just to play it safe, but Old Man immediately says "Ain't no way," and the haggling tug-of-war begins. After a tense back and forth, they shake on $7,000. It's a fairly steep price drop after the expert's high appraisal, but Bob seems relatively happy with the deal. Whoever ended up buying the book was no doubt even happier to own such a rich piece of scientific history.
