In the case of Realm of the Incas by Victor W. Von Hagen, I'm happy that it was available. Von Hagen was an explorer of Central and South America who published several dozen books on archaeological and anthropological topics in the 40's, 50's, and 60's, many in very inexpensive mass market paperback editions, so I'm guessing he was quite widely read in those decades. Given this output, I find it fascinating that it appears only one of these volumes (a book on the Maya) got reissued in a later edition (in the 90's). The current title was initially published n 1957, and the copy I have is from the seventh printing in 1963 (it's interesting how many scans of this are out there with various now-amazingly-low cover prices, this one having originally been priced at 60¢!).
As long-time readers may recall, I've traveled/studied in South America in the past, so I had a certain context for this book, and have read a modicum of historical books (aside from the shamanic and indigenous learning material) on the subject, and my impression of Realm of the Incas is that it brings the history and culture of the Incas to life more than any other book of its kind has. Of course, going in, with the evolving nature of archaeological/anthropological research, one has to wonder how much the “general knowledge” from half a century ago has held up over that time.
It appears that Von Hagen's specialty was in the study of roads (he has titles on other road systems and mentioned particular expeditions in this), and certainly that's a great place to start when looking at the Incas. Back in the 80's I was fortunate to be able to be on a program in which we hiked “the Inca Trail” from Cuzco to Machu Picchu, so I had a certain familiarity with this, and even with some of locations discussed. However, this was only one aspect of this look at Peru's great empire.
The book in in four sections, a historical background where pre-Inca cultures are noted (the Inca were a fairly late evolution in their region, from vague origins around 1,000 CE through the Spanish conquest and consolidation of control in the mid-1,500's), a look at the Inca people and their environment in 16 specific elements (ranging from the Allyu, a community structure still in use with the natives, to the Mita, the “service tax” imposed on the people), a consideration of the person of the Inca and the capital at Cuzco, and, lastly, a look at the Incan cultural achievements, from the notable architecture to the Quipu system of record-keeping via knots in cords.
Again, I am hesitant to “speak for the research” here, given that the author covers so wide a spectrum of elements (on which he could hardly be an expert across the board), and that he was an “adventurer” writing in the 50's (where aspects might well have been “romanced” to a certain extent), but most of this rings true from my experience and background on the subject, and he certainly “brings it to life” more than most.
Given this, I'm somewhat amazed that Realm of the Incas did not seem to have a printing past 1963, and I'm wondering why his other forty-some-odd books have likewise not been re-issued (books published through 1963 might well be in public domain at this point, if the copyright owner wasn't actively renewing it). However, I was also pleased to see that there are quite a lot of used copies, even up to “like new” (the one I got at Newberry was probably no better than “good”), for very little … in fact, one of the Amazon new/used guys has a “like new” copy of this for just a penny (plus, of course, the $3.99 shipping), so you can get a hold of this if it sounds like something (and if you have an interest in the Incan empire, you should get a copy!) you want to check out.