Kemo Sabi, which way did they go?
Finally there is:
The GENERAL STUD BOOK, Containing Pedigrees Of English Race Horses, &C, &C., From The Earliest Accounts To The Year 1831, Inclusive, With An Appendix, Giving Extended Pedigrees Of Stallions Imported Into The U.S., And Their Most Noted Progeny. . The price then was $125. Today it will cost you exactly 20 times that: $2,500
So what I have I found? In a nut shell it looks like this. American non-fiction imprints, early fiction and American manuscripts have done well. They now orbit the earth at significant multiples to what they sold for twenty years ago. Later unsigned fiction and random other books that have been exposed as common now languish on the net, sometimes at only 20% of the asking price of the 1980s. And then there are the zingers. These are the items that Mr. Leach appreciated that the market has since lost sight. Such items occasionally reappear at illogically low prices and are great fun to identify and acquire. In doing this assignment I ran across two copies on ABE of the "Confession of Michael Martin or Captain Lightfoot who was hung at Cambridge, Massachusetts, in the year 1821, for the robbery of Captain [with] An Account of Dr. John Wilson, who recently died at Brattleboro', Vt., believed by many to be the notorious Captain Thunderbolt." This is a 6.5" x 9.75" 44 page pamphlet paginated as 1-30, 2 and 1-12 and sewn together. This copy cost $56.15 including shipping. A small portion of the cover is torn away. There is one more copy on line priced at $125. Mr. Leach's price in 1983 was $75.
Make your study and reach your own conclusions. It's a fascinating field.