Don't forget when the book/variety is first getting publicity there are not many found yet, so pricing will be higher, as the word gets out and people begin to hunt them down, many more examples will be "found" and will come into the marketplace, lowering the values dramatically.
This happened on many TOP100 VAMs after the book was out for a year or so, case in point the 1887-P DDO
"Alligator Eye" VAM-11 became known as fairly common, I had a roll of MS63/64 dollars assembled within 4 months, sold while they were hot and bringing several hundred dollars each.
Many other VAMs became even rarer than previously thought, as well as many new VAMs have been found since the initial publication as more people entered the VAM
side of collecting. VAM
's are a bit more popular due to the sheer number of Morgan and Peace dollars
available, and the fact most people can't afford to collect every date and mint mark, it's easier to collect a subset of a single date of die pairings or a subset of VAMs like the TOP100 or HOT50 lists.
Buffalo nickels while very popular are not collected by die variety by nearly as many people as say VAMs are. The Buffalo collector usually wants the 3 legged variety and 1916 DDO
and 1917/8 and that it.
Also varieties that make it into printed album slots become very popular and "must haves" for set collectors ie: Lincoln cents 1922 plain, 1955 and 1972 DDOs, the rest of the DDOs and RPDs are only a very small subset for collectors and not usually required to have as a complete set.