I'm selling the book for what I think it's worth, my urgency to sell has passed so the price is staying as is. Letting buyers who know nothing about the book decide the price is silly. I know that the idea of buried treasure existing in the real world, outside of movies and iphones and video games seems ridiculous to the every day person, but the fact remains that it's there waiting for someone to find it.
The number of people interested in the hobby is probably slowly dwindling at best, they're more interested in the yearly consumer market treadmill of what new thing to buy this year that is marginally better than the one they got last year with a higher price tag.
Treasure, unlike this crap I just mentioned, doesn't change or lose its appeal. It sits there, for hundreds or thousands of years, still as valuable as the day it was buried, making its way into our stories and fantasies in forgotten books, or more commonly told on the big screen. It is the stuff of dreams, above the passing fancy of today's technology. It is not cheap, not to be thrown away and replaced like an overpriced electronic device. To me it means something, and if someone doesn't get that then they are not the kind of person I would deal with in this context.
If the atlas really was not valuable, then you'd be finding multiple copies for sale online at any given time. I treasure it, and I don't need 100 people to see it the same way as I do, 1 is enough.