You might be having difficulty finding some of the volumes of the Berserk manga that you wanted. In which case, Dark Horse, the series' English publisher, has some good news. Hard-to-find volumes 2, 5, 6, 12 and 14 are being reprinted, and are expected in stores on October 24th. They also mentioned that they are working on the last/latest volume (presumably 38, released in Japan in June and not yet here), and downplay the possibility of a digital version.
Attention BERSERK fans: Volumes 2, 5, 6, 12, and 14 are being re-released on Oct. 24th with more to come! pic.twitter.com/3bCxPmIwS0— Dark Horse Comics (@DarkHorseComics) September 28, 2016
@Nemesis_Reload We're still working on the final volume. It doesn't have a release date yet.— Dark Horse Comics (@DarkHorseComics) September 28, 2016
@Withafever digital rights for manga are extremely complicated to get so unfortunately it's unlikely this will be available on digital— Dark Horse Comics (@DarkHorseComics) September 28, 2016