Italian UFO Novelization

Hi everybody.

While putting my library in good order I found a book I bought in the
70s, which I found described in the UFO series home page:

http://ufoseries.com/books/index.html

under the name Italian UFO Novelization.

>Italian UFO Novelization: In 1975, a UFO novel by Paolo Proserpio
>was published in Italy. This 139 page hardback contained a
>novelization of the UFO episodes IDENTIFIED, EXPOSED, SURVIVAL,
>CONFLICT, E.S.P., and ORDEAL, and featured 5 photographs. Here are
>some scans (courtesy of Angelo Zumbo):

does somebody now how much is it worth ?

Thanx.