There are so few aulochromes that only a few collectors could have one.
Well they are still build, but this is not true for other rare instruments.
It is a nice idea to have one museum collection with all possible members of the saxophone family in one wing, including a C-Bass made by Sax, the Georgeophone, the aulochrome, the straight C-mel, the pigtail tenor and a replica of the imensaphone.