The third shelf in my downstairs ‘display’ bookcase (previously) has the most headroom and is home to some of my tallest volumes. These are more or less expensive art-books of one kind or another. Costliest among them would have been the FMR Arcimboldo book with the black spine none-too-clearly visible on the left. At one time I had another couple of titles from the same I segni dell’uomo series, but those I had acquired second-hand, whereas I bought the one above new from their official outlet in Venice (during the same trip as I acquired the carnival masks mentioned below).
The Opus Magnum volume cost me in the region of £150 - which seemed like a lot at the time but is I think a better price than one could find a copy for nowadays. And I could easily have paid £100 or so for the blue-spined book about Athanasius Kircher. I’ve had all those for between 15-25 years. Slightly more recently-acquired were the 2014 edition of The New Sylva (the red-spined volume on the right), and the Rizzoli printing of the Codex Seraphinianus; with the latest arrival of all being the Taschen Piranesi book which came into my hands last year. I had owned an Italian volume about Piranesi for some time which was pretty good, but where the reproductions of his etchings left something to be desired: the illustrations are larger and clearer in the Taschen edition.