Apparently there are indeed two editions. The Amazon states "Paperback" at 53€, Elektor sells it for nearly 70€ with specs "gebunden" which says "hardcover to me. I would go for the more expensive version at Elektor then.
Sembra che la edizione cara sia davvero quella con copertina rigida = "gebunden" in Tedesco.
BTW: just discovered that book thanks to that question. I guess, I will order it at Elektor.
EDIT:
Just ordered the hardcover for 60€ at Thalia bookshop, the book is on sale there - don't know, whethere this is an option for you.