Mysterious books

This book written by Oscar Lapeña Marchena is available in Italian (but it's translated...from what?). You can see it on sale here. The mystery is where's the English translated version in the picture above? It's listed at an Italian book store (here) but...do they sell English books or this is just a mock-up? I'm confused. BTW, that cover is very subtle. Arf.

Another book which can be found at Google books but not anywhere else is "The Italian Sword and Sandal Film" written by Frank Burke (link). Does it exist?

And finally there's this fun one:

They're all very academic and expensive ( here ; $60 for 72 pages). The question is: why are there more books on the Sword & Sandal genre than actual books for the general public?