Have you seen many at all of this book? I saw one a couple months ago on Ebay but that's a scarce book.
There must have been hundreds of WD #1's for sale, unsold and sold, in the same three month time period.
On the Mystery Tales the census shows 3 graded copies, total, compared to Walking Dead #1 1st print's 1700+ and climbing.
On the Mystery Tales we haven't reached the point where there less buyers than sellers.
I lost the one on eBay the other night. They pop up from time to time. Obviously they are less obtainable than a WD 1 9.8. But you have to keep in mind that no one cared about this book until Richard Alpert asked a young John Locke which of the items (including the comic) were "his". The book went from being a $100 book in lower mid grade (like any other atlas sci fi mystery book of the time) to a $1100+ lower mid grade raw book almost overnight.
The book was featured in one scene as a prop.
Walking Dead has turned into a franchise.
The makers of Lost had to pick not just an unattainable Atlas book, but one from that title, which is notorious for the demand it has gained in the last eighteen months (as mentioned often enough in the GA section).
And it was a blink and you'll miss it appearance.